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Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 25, 2016	Feb. 17, 2017	Jun. 26, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 25, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
Trading Symbol	PBPB
Entity Registrant Name	Potbelly Corporation
Entity Central Index Key	0001195734
Current Fiscal Year End Date	--12-25
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		25,071,577
Entity Public Float			$ 250.6

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 25, 2016	Dec. 27, 2015
Current assets
Cash and cash equivalents	$ 23,379	$ 32,006
Accounts receivable, net of allowances of $78 and $14 as of December 25, 2016 and December 27, 2015, respectively	3,787	4,461
Inventories	3,365	3,159
Prepaid expenses and other current assets	8,020	10,155
Total current assets	38,551	49,781
Property and equipment, net	107,074	97,434
Indefinite-lived intangible assets	3,404	3,404
Goodwill	2,222	1,428
Deferred income taxes, non-current	19,410	18,439
Deferred expenses, net and other assets	4,784	4,021
Total assets	175,445	174,507
Current liabilities
Accounts payable	3,111	5,762
Accrued expenses	23,082	19,277
Accrued income taxes	1,622	143
Total current liabilities	27,815	25,182
Deferred rent and landlord allowances	21,076	17,820
Other long-term liabilities	2,318	1,292
Total liabilities	51,209	44,294
Equity
Common stock, $0.01 par value—authorized, 200,000,000 shares; outstanding 25,139,127 and 26,304,261 shares as of December 25, 2016 and December 27, 2015, respectively	309	303
Warrants	909	909
Additional paid-in-capital	407,622	399,458
Treasury stock, held at cost, 5,753,412 and 4,033,910 shares as of December 25, 2016, and December 27, 2015, respectively	(72,321)	(50,000)
Accumulated deficit	(213,034)	(221,246)
Total stockholders’ equity	123,485	129,424
Non-controlling interest	751	789
Total equity	124,236	130,213
Total liabilities and equity	$ 175,445	$ 174,507

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 25, 2016	Dec. 27, 2015
Statement Of Financial Position [Abstract]
Allowances on accounts receivable	$ 78	$ 14
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	200,000,000	200,000,000
Common stock, outstanding	25,139,127	26,304,261
Treasury stock, shares	5,753,412	4,033,910

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Revenues
Sandwich shop sales, net	$ 404,874	$ 370,954	$ 325,464
Franchise royalties and fees	2,257	1,895	1,515
Total revenues	407,131	372,849	326,979
Sandwich shop operating expenses
Cost of goods sold, excluding depreciation	111,026	105,614	93,688
Labor and related expenses	117,838	106,628	93,165
Occupancy expenses	52,444	46,762	41,389
Other operating expenses	43,738	39,869	34,669
General and administrative expenses	40,411	37,322	32,420
Depreciation expense	22,734	21,476	19,615
Pre-opening costs	1,786	2,160	1,634
Impairment and loss on disposal of property and equipment	4,141	3,589	3,128
Total expenses	394,118	363,420	319,708
Income from operations	13,013	9,429	7,271
Interest expense	134	221	179
Income before income taxes	12,879	9,208	7,092
Income tax expense	4,443	3,466	2,748
Net income	8,436	5,742	4,344
Net income (loss) attributable to non-controlling interest	224	114	(14)
Net income attributable to Potbelly Corporation	$ 8,212	$ 5,628	$ 4,358
Net income per common share attributable to common stockholders:
Basic	$ 0.32	$ 0.20	$ 0.15
Diluted	$ 0.31	$ 0.20	$ 0.14
Weighted average shares outstanding:
Basic	25,623,809	28,002,005	29,209,298
Diluted	26,231,367	28,634,396	30,275,061

Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Warrants [Member]	Additional Paid-in-Capital [Member]	Accumulated Deficit [Member]	Non-Controlling Interest [Member]
Beginning Balance at Dec. 29, 2013	$ 153,273	$ 291		$ 909	$ 383,077	$ (231,232)	$ 228
Beginning Balance, Common Shares at Dec. 29, 2013		29,148,029
Net income	4,344					4,358	(14)
Issuance of unrestricted common stock	432				432
Issuance of unrestricted common stock, Shares		28,240
Exercise of stock options	$ 5,059	$ 7			5,052
Exercise of stock options, Shares	586,000	585,521
Excess tax benefits associated with exercise of stock options	$ 1,300				1,300
Repurchases of common stock	(10,246)		$ (10,246)
Repurchases of common stock, Shares		(827,090)
Distributions to non-controlling interest	(46)						(46)
Contributions from non-controlling interest	98						98
Amortization of stock-based compensation	2,111				2,111
Ending Balance at Dec. 28, 2014	156,325	$ 298	(10,246)	909	391,972	(226,874)	266
Ending Balance, Common Shares at Dec. 28, 2014		28,934,700
Net income	5,742					5,628	114
Exercise of stock options	$ 4,784	$ 5			4,779
Exercise of stock options, Shares	576,000	576,381
Excess tax benefits associated with exercise of stock options	$ 308				308
Repurchases of common stock	(39,754)		(39,754)
Repurchases of common stock, Shares		(3,206,820)
Distributions to non-controlling interest	(198)						(198)
Contributions from non-controlling interest	607						607
Amortization of stock-based compensation	2,399				2,399
Ending Balance at Dec. 27, 2015	$ 130,213	$ 303	(50,000)	909	399,458	(221,246)	789
Ending Balance, Common Shares at Dec. 27, 2015	26,304,261	26,304,261
Net income	$ 8,436					8,212	224
Exercise of stock options	$ 5,776	$ 6			5,770
Exercise of stock options, Shares	536,000	536,332
Common stock issued for stock-based compensation plans, Shares		18,036
Excess tax deficiencies associated with exercise of stock options	$ (663)				(663)
Repurchases of common stock	$ (22,321)		(22,321)
Repurchases of common stock, Shares	(1,719,502)	(1,719,502)
Distributions to non-controlling interest	$ (413)						(413)
Contributions from non-controlling interest	151						151
Amortization of stock-based compensation	3,057				3,057
Ending Balance at Dec. 25, 2016	$ 124,236	$ 309	$ (72,321)	$ 909	$ 407,622	$ (213,034)	$ 751
Ending Balance, Common Shares at Dec. 25, 2016	25,139,127	25,139,127

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 8,436	$ 5,742	$ 4,344
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	22,734	21,476	19,615
Deferred income tax	(1,659)	(72)	(289)
Deferred rent and landlord allowances	3,256	3,808	1,787
Amortization of stock-based compensation	3,057	2,399	2,543
Excess tax benefit from stock-based compensation	(31)	(308)	(1,300)
Asset impairment, store closure and disposal of property and equipment	4,243	3,818	3,679
Amortization of debt issuance costs	34	11	70
Changes in operating assets and liabilities:
Accounts receivable, net	674	(445)	(1,013)
Inventories	(188)	(388)	(505)
Prepaid expenses and other assets	3,204	(1,155)	(4,216)
Accounts payable	(1,899)	1,876	1,301
Accrued and other liabilities	4,108	3,558	538
Net cash provided by operating activities	45,969	40,320	26,554
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of franchise shop	(1,108)	(333)
Purchases of property and equipment	(36,712)	(35,725)	(29,209)
Net cash used in investing activities	(37,820)	(36,058)	(29,209)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments on note payable		(1,008)	(84)
Proceeds from exercise of stock options	6,165	5,825	6,137
Payment of payroll taxes related to stock-based compensation awards	(389)	(1,041)	(1,078)
Excess tax benefit from stock-based compensation	31	308	1,300
Treasury stock repurchase	(22,321)	(39,754)	(10,246)
Contributions from non-controlling interest	151	607	98
Distributions to non-controlling interest	(413)	(198)	(46)
Net cash used in financing activities	(16,776)	(35,261)	(3,919)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(8,627)	(30,999)	(6,574)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	32,006	63,005	69,579
CASH AND CASH EQUIVALENTS AT END OF PERIOD	23,379	32,006	63,005
Supplemental cash flow information :
Income taxes paid	3,663	2,376	3,232
Interest paid	108	183	179
Supplemental non-cash investing and financing activities :
Unpaid liability for purchases of property and equipment	$ 2,727	$ 3,395	$ 2,690

Organization and Other Matters	12 Months Ended
Organization and Other Matters	Dec. 25, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Other Matters	(1) Organization and Other Matters Business Potbelly Corporation (the “Company” or “Potbelly”), through its wholly-owned subsidiaries, operates Potbelly Sandwich Works sandwich shops in 29 states and the District of Columbia. The Company also sells and administers franchises of Potbelly Sandwich Works sandwich shops. The first franchise locations administered by the Company opened during February 2011. In July 2015, the Company opened its first franchise shop in the United Kingdom, and in October 2016, the Company opened its first franchise shop in Canada. Additionally, during each of July 2015 and April 2016, the Company transitioned one franchise shop into a company-operated shop for a purchase price of $0.3 million and $1.1 million, respectively. The Company did not record any goodwill related to the July 2015 transaction and recorded $0.8 million of goodwill related to the April 2016 transaction. The Company believes both acquisitions are immaterial. Initial Public Offering On October 9, 2013, the Company completed an initial public offering (“IPO”) of 8,625,000 shares of common stock, which included 1,125,000 shares of common stock issued upon the exercise in full of the underwriters’ option to purchase additional shares. The Company sold 8,474,869 shares of common stock and certain stockholders sold 150,131 shares of common stock. The Company received net proceeds from the offering of approximately $108.8 million, after deducting the underwriting discount and other offering expenses. The Company did not receive any proceeds from the shares sold by the selling stockholders. The Company used the net proceeds received from the sale of its shares to pay a previously-declared one-time cash dividend of $49.9 million on shares outstanding on October 8, 2013 and also to repay borrowings of approximately $14.0 million under its senior credit facility. During fiscal year 2014, the Company used approximately $10.2 million of the net proceeds to repurchase common stock pursuant to the share repurchase program authorized by the Company’s Board of Directors on August 1, 2014. The remaining proceeds were used in fiscal year 2015 for share repurchases, working capital, and general corporate purposes.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 25, 2016

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

(2) Summary of Significant Accounting Policies

(a) Principles of Consolidation

The consolidated financial statements include the accounts of Potbelly Corporation; its wholly owned subsidiary, Potbelly Illinois, Inc. (“PII”); PII’s wholly owned subsidiaries, Potbelly Franchising, LLC and Potbelly Sandwich Works LLC (“LLC”); eight of LLC’s wholly owned subsidiaries and LLC’s five joint ventures, collectively, the “Company.” All significant intercompany balances and transactions have been eliminated in consolidation. For consolidated joint ventures, non-controlling interest represents a non-controlling partner’s share of the assets, liabilities and operations related to the five joint venture investments. The Company has ownership interests ranging from 51-80% in these consolidated joint ventures.

The Company does not have any components of other comprehensive income (loss) recorded within its consolidated financial statements, and, therefore, does not separately present a statement of comprehensive income (loss) in its consolidated financial statements.

(b) Reporting Period

The Company uses a 52/53-week fiscal year that ends on the last Sunday of the calendar year. Approximately every five or six years a 53rd week is added. Fiscal years 2014, 2015 and 2016 each consisted of 52 weeks.

The Company owns and operates Potbelly Sandwich Works sandwich shops in the United States. The Company also has domestic and international franchise operations of Potbelly Sandwich Works sandwich shops. The Company’s chief operating decision maker (the “CODM”) is its Chief Executive Officer. As the CODM reviews financial performance and allocates resources at a consolidated level on a recurring basis, the Company has one operating segment and one reportable segment.

(d) Use of Estimates

The preparation of financial statements in conformity with generally accepted accounting principles in the United States (“GAAP”) requires management to make estimates and assumptions, primarily related to the long-lived assets and income taxes, that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

(e) Fair Value Measurements

The Company applies fair value accounting for all financial assets and liabilities and nonfinancial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities that are required to be recorded at fair value, the Company assumes the highest and best use of the asset by market participants in which the Company would transact and the market-based risk measurements or assumptions that market participants would use in pricing the asset or liability, such as inherent risk, transfer restrictions, and credit risk.

The Company applies the following fair value hierarchy, which prioritizes the inputs used to measure fair value into three levels, and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement:

•

Level 1—Quoted prices in active markets for identical assets or liabilities.

•

Level 2—Observable inputs other than quoted prices in active markets for identical assets or liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

•

Level 3—Inputs that are both unobservable and significant to the overall fair value measurement reflect an entity’s estimates of assumptions that market participants would use in pricing the asset or liability.

(f) Financial Instruments

The Company records all financial instruments at cost, which is the fair value at the date of transaction. The amounts reported in the consolidated balance sheets for cash and cash equivalents, accounts receivable, accounts payable and all other current liabilities approximate their fair value because of the short-term maturities of these instruments.

(g) Cash and Cash Equivalents

The Company considers all highly liquid investment instruments with an original maturity of three months or less when purchased to be cash equivalents. The Company maintains its cash in bank deposit accounts that, at times, may exceed federally insured limits; however, the Company has not experienced any losses in these accounts. The Company believes it is not exposed to any significant credit risk. These are valued within the fair value hierarchy as Level 1 measurements.

(h) Accounts Receivable, net

Accounts receivable, net consists of credit card receivables, amounts owed from vendors and miscellaneous receivables. The Company had credit card receivables of $2.0 million and $1.6 million as of December 27, 2015 and December 25, 2016, respectively.

(i) Inventories

Inventories, which consist of food products, paper goods and supplies, and promotional items, are valued at the lower of cost (first-in, first-out) or market. No adjustment is deemed necessary to reduce inventory to the lower of cost or market value due to the rapid turnover and high utilization of inventory.

(j) Property and Equipment

Property and equipment acquired is recorded at cost less accumulated depreciation. Property and equipment is depreciated based on the straight-line method over the estimated useful lives, generally ranging from three to five years for furniture and fixtures, computer equipment, computer software, and machinery and equipment. Leasehold improvements are depreciated over the shorter of their estimated useful lives or the related lease life, generally 10 to 15 years. For leases with renewal periods at the Company’s option, the Company determines the expected lease period based on whether the renewal of any options are reasonably assured at the inception of the lease.

Direct costs and expenditures for refurbishments and improvements that significantly add to the productive capacity or extend the useful life of an asset are capitalized, whereas the costs of repairs and maintenance are expensed when incurred. The Company capitalizes certain internal costs associated with the development, design, and construction of new shop locations as these costs have a future benefit to the Company. The Company capitalized costs of $0.9 million, $0.6 million and $0.6 million for the fiscal years ended December 28, 2014, December 27, 2015 and December 25, 2016, respectively. Capitalized costs are recorded as part of the asset to which they relate, primarily to leasehold improvements, and such costs are amortized over the asset’s useful life. When assets are retired or sold, the asset cost and related accumulated depreciation are removed from the consolidated balance sheet and any gain or loss is recorded in the consolidated statement of operations.

The Company assesses potential impairments to its long-lived assets, which includes property and equipment, on a quarterly basis or whenever events or circumstances indicate that the carrying amount of an asset may not be recoverable. Shop-level assets are grouped at the individual shop-level for the purpose of the impairment assessment. Recoverability of an asset is measured by a comparison of the carrying amount of an asset to its estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of the asset group exceeds its estimated undiscounted future cash flows, an impairment charge is recognized as the amount by which the carrying amount of the asset exceeds the fair value of the asset. The fair value of the shop assets is determined using the discounted future cash flow method of anticipated cash flows through the shop’s lease-end date using fair value measurement inputs classified as Level 3. Level 3 inputs are derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. The Company used a weighted average cost of capital to discount the future cash flows. After performing periodic reviews of the company-operated shops during each quarter of 2014, 2015 and 2016, it was determined that indicators of impairment were present for certain shops as a result of continued underperformance. The Company performed an impairment analysis related to these shops and recorded impairment charges of $2.9 million, $3.4 million and $4.0 million for the fiscal years 2014, 2015 and 2016, respectively, which is included in impairment and loss on disposal of property and equipment in the consolidated statements of operations.

(k) Intangible Assets

The Company reviews indefinite-lived intangible assets, which includes goodwill and tradenames, annually at fiscal year-end for impairment or more frequently if events or circumstances indicate that the carrying value may not be recoverable. An impaired asset is written down to its estimated fair value based on the most recent information available. The Company assesses the fair values of its intangible assets, and its reporting unit for goodwill testing purposes, using both an income-based approach and a market approach. Under the income approach, fair value is based on the present value of estimated future cash flows. The income approach is dependent on a number of factors, including forecasted revenues and expenses, appropriate discount rates and other variables. The market approach measures fair value by comparison to the observed fair values of comparable companies, adjusted for the relative size and profitability of these comparable companies. The annual impairment review utilizes the estimated fair value of the intangible assets and the overall reporting unit and compares the estimated fair values to the carrying values as of the testing date. If the carrying value of these intangible assets or the reporting unit exceeds the fair values, the Company would then use the fair values to measure the amount of any required impairment charge. No impairment charge was recognized for intangible assets for any of the fiscal periods presented.

(l) Pre-opening Costs

Pre-opening costs consist of costs incurred prior to opening a new shop and are made up primarily of travel, employee payroll and training costs incurred prior to the shop opening, as well as occupancy costs incurred from when the Company takes site possession to shop opening. Shop pre-opening costs are expensed as incurred.

(m) Advertising Expenses

Advertising costs are expensed as incurred and are included in general and administrative expenses in the consolidated statements of operations. Advertising expenses were $2.2 million, $2.9 million and $3.0 million in fiscal years 2014, 2015 and 2016, respectively.

(n) Income Taxes

Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are attributable to differences between financial statement and income tax reporting. Deferred tax assets, net of any valuation allowances, represent the future tax return consequences of those differences and for operating loss and tax credit carryforwards, which will be deductible when the assets are recovered. Deferred tax assets are reduced by a valuation allowance if it is deemed more likely than not that some or all of the deferred tax assets will not be realized. In making this assessment of realizability of deferred tax assets, the Company considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. The Company considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. Deferred tax liabilities are recognized for temporary differences that will be taxable in future years’ tax returns.

The Company accounts for uncertain tax positions under current accounting guidance, which prescribes a minimum probability threshold that a tax position must meet before a financial statement benefit is recognized. The minimum threshold is defined as a tax position that is more likely than not to be sustained upon examination by tax authorities, based on the technical merits of the position. The tax benefit to be recognized is measured as the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement.

(o) Stock-Based Compensation

The Company has granted stock options under its 2001 Equity Incentive Plan (the “2001 Plan”), 2004 Equity Incentive Plan (the “2004 Plan”) and 2013 Long-Term Incentive Plan, as amended (the “2013 Plan” and together with the 2004 Plan and 2001 Plan, the “Plans”). The Plans permit the granting of awards to employees and non-employee officers, consultants, agents, and independent contractors of the Company in the form of stock appreciation rights, stock awards, and stock options. The Plans give broad powers to the Company’s board of directors to administer and interpret the Plans, including the authority to select the individuals to be granted options and rights and to prescribe the particular form and conditions of each option to be granted. In September 2011, the 2001 Plan expired with options outstanding under the plan still available for exercise. On July 31, 2013, the Company’s board of directors approved the adoption of the 2013 Plan, which replaced the 2004 Plan in conjunction with the Company’s IPO. Upon approval of the 2013 Plan, the Company no longer issued awards under the 2004 Plan. The 2004 Plan expired in February 2014, but will continue to govern outstanding awards granted prior to its termination.

The Company accounts for its stock-based employee compensation in accordance with Accounting Standards Codification (“ASC”) 718, Stock Based Compensation. The Company records stock compensation expense on a straight-line basis over the vesting period based on the grant-date fair value of the option, determined using the Black-Scholes option pricing valuation model.

(p) Leases

The Company leases retail shops, warehouse and office space under operating leases. Most lease agreements contain tenant improvement allowances, rent holidays, lease premiums, rent escalation clauses, and/or contingent rent provisions. For purposes of recognizing incentives, premiums, and minimum rental expenses on a straight-line basis over the terms of the leases, the Company uses the date it takes possession of the leased space for construction purposes as the beginning of the term, which is generally two to three months prior to a shop’s opening date. For leases with renewal periods at the Company’s option, the Company determines the expected lease period based on whether the renewal of any options are reasonably assured at the inception of the lease. In addition to rental expense, certain leases require the Company to pay a portion of real estate taxes, utilities, building operating expenses, insurance and other charges in addition to rent.

For tenant improvement allowances, rent escalations, and rent holidays, the Company records a deferred rent liability in its consolidated balance sheets and amortizes the deferred rent over the terms of the leases as reductions to occupancy expense in the consolidated statements of operations.

(q) Revenue Recognition

Revenue from retail shops are presented net of discounts and recognized when food and beverage products are sold. Sales taxes collected from customers are excluded from revenues and the obligation is included in accrued liabilities until the taxes are remitted to the appropriate taxing authorities.

Revenues from the Company’s gift cards are deferred and were previously recognized upon redemption or after a period of 36 months of inactivity on gift card balances (“gift card breakage”) and the Company does not have a legal obligation to remit the value of the unredeemed gift cards to the relevant jurisdictions. The Company monitors its actual patterns of redemption and updates its estimates and assumptions regarding redemption as the actual pattern changes. The Company estimates and records gift card breakage income based on its historical redemption pattern. The Company recognized an immaterial amount of gift card breakage income for the fiscal years ended 2014, 2015 and 2016, which is recorded within other operating expenses in the consolidated statements of operations.

The Company earns an initial franchise fee, a franchise development agreement fee and ongoing royalty fees under the Company’s franchise agreements. Initial franchise fee revenue is recognized at the point a franchise shop opens for business to the public, as this is the point in time when the Company has substantially performed all initial services required under the franchise agreement. The Company recognized franchise fee revenue of $0.3 million, $0.4 million and $0.4 million in fiscal year 2014, 2015 and 2016, respectively. Initial franchise fee payments received by the Company before the shop opens are recorded as deferred revenue in the consolidated balance sheet. The Company had deferred revenue related to initial franchise fees of $0.5 million and $0.7 million included in accrued expenses as of December 27, 2015 and December 25, 2016, respectively. Franchise development agreement fee represents the exclusivity rights for a geographical area paid by a third party to develop Potbelly shops for a certain period of time. Franchise development agreement fee payments received by the Company are recorded as deferred revenue in the consolidated balance sheet and amortized over the life of the franchise development agreement. The Company had deferred revenue related to franchise development agreement fees of $0.4 million recorded as accrued expenses as of December 27, 2015 and December 25, 2016. Royalty fees are based on a percentage of sales and are recorded as revenue as the fees are earned and become receivable from the franchisee. The Company recognized royalty fees revenue of $1.2 million, $1.5 million and $1.9 million for fiscal years 2014, 2015, and 2016, respectively.

(r) Recent Accounting Pronouncements

In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers.” The pronouncement was issued to clarify the principles for recognizing revenue and to develop a common revenue standard and disclosure requirements for U.S. GAAP and IFRS. The FASB has approved a one-year deferral of the effective date of ASU 2014-09, such that it will become effective for the annual period beginning after December 15, 2017. In addition, the FASB issued ASU 2016-08, ASU 2016-10, ASU 2016-12, and ASU 2016-20 in March 2016, April 2016, May 2016, and December 2016, respectively, to help provide interpretive clarifications on the new guidance in ASC Topic 606. The Company is currently evaluating the overall impact that ASU 2014-09 will have on the Company's consolidated financial statements, as well as the expected timing and method of adoption. Based on a preliminary assessment, the Company has determined that the adoption will not have a material impact on sandwich shop sales, but may impact gift card breakage income. The Company is continuing its assessment, which may identify additional impacts this standard will have on its consolidated financial statements and related disclosures.

In February 2016, the FASB issued ASU No. 2016-02, “Leases”, which will replace the existing guidance in ASC 840, “Leases”. The pronouncement requires a dual approach for lessee accounting under which a lessee would account for leases as finance leases or operating leases. Both finance leases and operating leases will result in the lessee recognizing a right-of-use asset and a corresponding lease liability. For finance leases, the lessee would recognize interest expense and amortization of the right-of-use asset, and for operating leases, the lessee would recognize a straight-line total lease expense. The pronouncement is effective for fiscal years beginning after December 15, 2018, including annual and interim periods thereafter. In addition, the pronouncement requires the use of the modified retrospective method, which will require adjustment to all comparative periods presented in the consolidated financial statements. The Company is currently evaluating the impact ASU 2016-02 will have on its financial position, results of operations and cash flows but expect that it will result in a material increase in its long-term assets and liabilities given the Company has a significant number of leases.

In March 2016, the FASB issued ASU No. 2016-04, “Recognition of Breakage for Certain Prepaid Stored-Value Products”. This pronouncement clarifies when it is acceptable to recognize the unredeemed portion of prepaid gift cards into income. This pronouncement is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company is evaluating the impact this standard will have on its financial statements and disclosures.

In March 2016, the FASB issued ASU No. 2016-09, “Compensation – Stock Compensation (Topic 718)”. The pronouncement simplifies the accounting for the taxes related to stock-based compensation, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification within the statement of cash flows. The pronouncement is effective for annual periods beginning after December 15, 2016, including annual and interim periods thereafter. If the Company would have adopted this standard for fiscal 2016, it would have had the effect of increasing income tax expense by $0.7 million for the year.

In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments”. The objective of this pronouncement is to eliminate the diversity in practice related to the classification of certain cash receipts and payments in the statement of cash flows, by adding or clarifying guidance on eight specific cash flow issues. The pronouncement is effective for annual periods beginning after December 15, 2017, including annual and interim periods thereafter. Early adoption is permitted. The adoption of ASU 2016-15 is not expected to have a material effect on the Company’s financial statements and disclosures.

(s) Commitments and Contingencies

As previously disclosed in prior reports filed with the SEC, the Company received notice of a potential claim alleging that the Company violated the Fair Labor Standards Act by not paying overtime to its assistant managers, whom the Company has classified as exempt employees. Although the Company has always believed that its assistant managers are properly classified as exempt under both federal and state laws, and have always intended to defend any such lawsuits vigorously, the Company agreed to mediate the matter. On February 20, 2017, the parties entered into a Settlement Agreement and Release whereby participating assistant managers will release the Company from all federal and/or state wage and hour claims in exchange for a gross settlement amount of $1.3 million. As part of the settlement process, a complaint was filed on February 17, 2017 in the Circuit Court of the Fifteenth Judicial Circuit in and for Palm Beach County, Florida, and a motion seeking the Court's preliminary approval of the settlement was filed on February 21, 2017. As of December 25, 2016, the Company recorded a liability of $1.3 million for this matter. The settlement of this action did not have a material adverse effect on our financial position or results of operations and cash flows.

The Company is subject to legal proceedings, claims and liabilities, such as employment-related claims and slip and fall cases, which arise in the ordinary course of business and are generally covered by insurance. In the opinion of management, the amount of ultimate liability with respect to those actions should not have a material adverse impact on the Company’s financial position, results of operations or cash flows.

Many of the food products the Company purchases are subject to changes in the price and availability of food commodities, including, among other things, beef, poultry, grains, dairy and produce. The Company works with its suppliers and uses a mix of forward pricing protocols for certain items including agreements with its supplier on fixed prices for deliveries at some time in the future and agreements on a fixed price with its supplier for the duration of that protocol. The Company also utilizes formula pricing protocols under which the prices the Company pays are based on a specified formula related to the prices of the goods, such as spot prices. The Company’s use of any forward pricing arrangements varies substantially from time to time and these arrangements tend to cover relatively short periods (i.e., typically twelve months or less). Such contracts are used in the normal purchases of the Company’s food products and not for speculative purposes, and as such are not required to be evaluated as derivative instruments. The Company does not enter into futures contracts or other derivative instruments.

Fair Value Measurement	12 Months Ended
Fair Value Measurement	Dec. 25, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurement	(3) Fair Value Measurement The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and all other current liabilities approximate fair values due to the short maturities of these balances. The Company assesses potential impairments to its long-lived assets, which includes property and equipment, on a quarterly basis, or whenever events or circumstances indicate that the carrying amount of an asset may not be recoverable. Shop-level assets are grouped at the individual shop-level for the purpose of the impairment assessment. Recoverability of an asset is measured by a comparison of the carrying amount of an asset to its estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of the asset group exceeds its estimated undiscounted future cash flows, an impairment charge is recognized as the amount by which the carrying amount of the asset exceeds the fair value of the asset. The fair value of the shop assets was determined using the discounted future cash flow method of anticipated cash flows through the shop’s lease-end date using fair value measurement inputs classified as Level 3. Level 3 inputs are derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. After performing a periodic review of the Company’s shops during each quarter of 2014, 2015 and 2016, it was determined that indicators of impairment were present for certain shops as a result of continued underperformance of shop profitability. The Company performed an impairment analysis related to these shops and recorded impairment charges of $2.9 million, $3.4 million and $4.0 million for the fiscal years 2014, 2015 and 2016, respectively, related to the excess of the carrying amounts recorded on the Company’s consolidated balance sheet over the identified shops’ estimated fair values.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Earnings per Share

12 Months Ended

Dec. 25, 2016

Earnings Per Share [Abstract]

Earnings per Share

(4) Earnings per share

Basic and diluted income per common share attributable to common stockholders are calculated using the weighted average number of common shares outstanding for the period. Diluted income per common share attributable to common stockholders is computed by dividing the income allocated to common stockholders by the weighted average number of fully diluted common shares outstanding.

	Fiscal Year
	2016		2015		2014
Net income attributable to Potbelly Corporation	$	8,212	$	5,628	$	4,358
Weighted average common shares outstanding-basic		25,623,809		28,002,005		29,209,298
Plus: Effect of potential stock options exercise		549,578		577,156		949,142
Plus: Effect of potential warrant exercise		57,980		55,235		116,621
Weighted average common shares outstanding-diluted		26,231,367		28,634,396		30,275,061
Income per share available to common stockholders-basic	$	0.32	$	0.20	$	0.15
Income per share available to common stockholders-diluted	$	0.31	$	0.20	$	0.14
Potentially dilutive shares that are considered anti-dilutive:
Common share options		1,164,047		898,966		622,879
Warrants		—		—		—

Property and Equipment

12 Months Ended

Dec. 25, 2016

Property Plant And Equipment [Abstract]

Property and Equipment

(5) Property and Equipment

Property and equipment, net consisted of the following (in thousands):

	December 25,			December 27,
	2016			2015
Leasehold improvements	$	170,196		$	157,556
Machinery and equipment		47,668			42,840
Furniture and fixtures		32,561			28,605
Computer equipment and software		23,162			20,077
Construction in progress		5,601			3,074
		279,188			252,152
Less: Accumulated depreciation		(172,114	)		(154,718	)
	$	107,074		$	97,434

Accrued Expenses

12 Months Ended

Dec. 25, 2016

Accrued Liabilities Current [Abstract]

Accrued Expenses

(6) Accrued Expenses

Accrued expenses consisted of the following (in thousands):

	December 25,		December 27,
	2016		2015
Accrued labor and related expenses	$	6,120	$	7,482
Deferred gift card revenue		2,292		1,843
Accrued occupancy expenses		1,538		672
Deferred rent—current		706		813
Accrued corporate and shop expenses		2,255		1,961
Accrued utilities		1,094		1,035
Accrued sales and use tax		1,857		1,820
Accrued construction		2,329		2,271
Accrued contract termination costs (a)		28		21
Accrued legal and professional fees		1,756		136
Accrued other		3,107		1,223
Total	$	23,082	$	19,277

(a)	The Company incurs expenses associated with exit activity for certain signed lease agreements, which are recognized in general and administrative expenses. Accrued contract termination costs consisted of the following (in thousands):

	December 25,			December 27,
	2016			2015
Accrued contract termination costs—beginning balance	$	21		$	801
Contract termination costs incurred		24			—
Contract termination costs settled and paid		(17	)		(780	)
Accrued contract termination costs—ending balance	$	28		$	21

Income Taxes

12 Months Ended

Dec. 25, 2016

Income Tax Disclosure [Abstract]

Income Taxes

(7) Income Taxes

Income before income taxes for the Company’s domestic and foreign operations was as follows (in thousands):

	Fiscal Year
	2016		2015		2014
Domestic operations	$	12,411	$	8,660	$	6,627
Foreign operations		468		548		465
Total	$	12,879	$	9,208	$	7,092

Income tax expense consisted of the following (in thousands):

	Fiscal Year
	2016			2015			2014
Federal:
Current	$	4,652		$	2,450		$	2,386
Deferred		(1,386	)		209			(467	)
		3,266			2,659			1,919
State and Local:
Current		1,426			1,047			622
Deferred		(273	)		(281	)		178
		1,153			766			800
Foreign:
Current		24			41			29
Deferred		—			—			—
		24			41			29
Income tax expense	$	4,443		$	3,466		$	2,748

Income tax expense differed from the amounts computed by applying the U.S. federal income tax rates to income before income taxes as a result of the following (in thousands):

	Fiscal Year
	2016			2015			2014
Computed “expected” tax expense	$	4,508		$	3,223		$	2,411
Increase (reduction) resulting from:
Minority interest		(89	)		(45	)		—
Permanent differences		131			51			97
State and local income taxes, net of federal income tax effect		673			533			460
FICA and other tax credits		(556	)		(392	)		(222	)
Rate change and true-ups (a)		(224	)		164			2
Change in valuation allowance		—			(68	)		—
	$	4,443		$	3,466		$	2,748

(a)	The $(224) of rate changes and true-ups relates primarily to a favorable provision-to-return adjustment related to WOTC credits.

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities reflected in the consolidated balance sheets are presented below (in thousands):

	December 25,			December 27,
	2016			2015
Deferred tax assets:
Accrued liabilities	$	1,848		$	2,074
Deferred revenue on gift certificates and gift cards		323			141
Stock-based compensation		8,104			8,261
Property and equipment depreciation		6,293			5,805
Deferred rent and start-up amortization		5,656			4,650
Other timing differences		234			273
FICA and other tax credits		—			43
Total deferred tax assets		22,458			21,247
Less: valuation allowance		—			—
Net deferred tax assets		22,458			21,247
Deferred tax liabilities:
Prepaids		(635	)		(547	)
Intangible asset		(1,351	)		(1,226	)
Smallwares		(801	)		(733	)
Other timing differences		(261	)		(302	)
Total gross deferred tax liabilities		(3,048	)		(2,808	)
Net deferred tax assets	$	19,410		$	18,439

As of December 27, 2015 and December 25, 2016, the Company has no valuation allowances recorded based on management’s assessment of the amount of its deferred tax assets that are more likely than not to be realized.

In accordance with its accounting policy, the Company recognizes accrued interest and penalties related to unrecognized tax benefits as a component of income tax expense. As of December 27, 2015 and December 25, 2016, the Company had no interest or penalties accrued.

The tax years prior to 2013 are generally closed for examination by the United States Internal Revenue Service. However, certain of these tax years are open for examination as a result of net operating losses generated in these years and utilized in subsequent years. The Company is currently under examination with the IRS for the 2014 tax year; no other IRS audits are currently ongoing. State statutes are generally open for audit for the 2012 to 2016 tax years. Additionally, certain tax years through 2016 are open for examination by certain state tax authorities.

Long-term Debt	12 Months Ended
Long-term Debt	Dec. 25, 2016
Debt Disclosure [Abstract]
Long-term Debt	(8) Long-term debt Note payable On March 15, 2007, the Company entered into a long-term note payable associated with the acquisition of certain assets of Pot Belly Deli, Inc., an unrelated California company, including the Pot Belly trade name, certain design marks, and other related assets. The Company records interest on the note payable under the effective interest method at an annual interest rate of 6.2% and recorded interest expense of $0.1 million in fiscal year 2014. The Company recorded an immaterial amount of interest expense on the note payable in fiscal year 2015. Payment of interest and principal is made monthly. The final repayment of the note was made on April 1, 2015. Credit facility JPMorgan Chase Bank, N.A. On December 9, 2015, the Company entered into an amended and restated five-year revolving credit facility agreement that expires in November 2020. The credit agreement provides, among other things, for a revolving credit facility in a maximum principal amount of $50 million, with possible future increases to $75 million under an expansion feature. Borrowings under the credit facility generally bear interest at the Company’s option at either (i) a eurocurrency rate determined by reference to the applicable LIBOR rate plus a margin ranging from 1.00% to 1.75% or (ii) a prime rate as announced by JP Morgan Chase plus a margin ranging from 0.00% to 0.50%. The applicable margin is determined based upon the Company’s consolidated total leverage ratio. On the last day of each calendar quarter, the Company is required to pay a commitment fee ranging from 0.125% to 0.20% per annum in respect of any unused commitments under the credit facility, with the specific rate determined based upon the Company’s consolidated total leverage ratio. So long as certain total leverage ratios are met, there is no limit on the “restricted payments” (primarily distributions and equity repurchases) that the Company may make. As of December 25, 2016, the Company has no amounts outstanding under the credit facility. As of and for the year ended December 25, 2016, the Company has $49.3 million available for borrowing under the credit facility after reductions for outstanding letters of credit.

Capital Stock and Warrants	12 Months Ended
Capital Stock and Warrants	Dec. 25, 2016
Equity [Abstract]
Capital Stock and Warrants	(9) Capital Stock and Warrants As of December 25, 2016 and December 27, 2015, the Company had authorized an aggregate of 210,000,000 shares of capital stock, of which 200,000,000 shares were designated as common stock and 10,000,000 shares were designated as preferred stock. As of December 25, 2016, the Company had issued and outstanding 30,892,539 and 25,139,127 shares of common stock, respectively. As of December 27, 2015, the Company had issued and outstanding 30,338,171 and 26,304,261 shares of common stock, respectively. Common Stock As of December 25, 2016, each share of common stock has the same relative rights and was identical in all respects to each other share of common stock. Each holder of shares of common stock is entitled to one vote for each share held by such holder at all meetings of stockholders. On September 8, 2016, the Company announced that its Board of Directors authorized a share repurchase program of up to $30.0 million of the Company’s common stock. The Company’s previous $35.0 million share repurchase program, authorized in September 2015, was completed in July 2016. The new program permits the Company, from time to time, to purchase shares in the open market (including in pre-arranged stock trading plans in accordance with the guidelines specified in Rule 10b5-1 under the Securities Exchange Act of 1934, as amended) or in privately negotiated transactions. During the fiscal year ended December 25, 2016, the Company repurchased 1,719,502 shares of its common stock for approximately $22.3 million, including cost and commission, in open market transactions. As of December 25, 2016, the remaining dollar value of authorization under the share repurchase program was $27.7 million, which does not include commission. Repurchased shares are included as treasury stock in the consolidated balance sheets and the consolidated statements of equity. Warrants As of December 27, 2015 and December 25, 2016, the Company had 241,704 warrants outstanding. During 2013, the Company modified 241,704 of warrants issued to Oxford Capital Partners, Inc. that were set to expire upon the consummation of an IPO to extend the expiration date of such warrants to five years from the date of the consummation of an IPO. In accordance with ASC Topic 718, Compensation—Stock Compensation, the Company recorded a charge of approximately $0.1 million related to the incremental value associated with the extension of the expiration date.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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-Subparagraph (SX 210.5-02(29))
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-SubTopic 10
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-Subparagraph (SX 210.5-02(31))
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 9: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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+ Details

Operating Leases

12 Months Ended

Dec. 25, 2016

Leases [Abstract]

Operating Leases

(10) Operating Leases

The Company leases office space for its corporate office and commercial spaces for its shops under various long-term operating lease agreements. The leases for the Company’s shop locations generally have initial terms of 10 years and typically provide for two renewal options in five-year increments as well as for rent escalations. These leases expire or become subject to renewal clauses at various dates from 2017 to 2029. Some of the leases provide for base rent, plus additional rent based on gross sales, as defined in each lease agreement. The Company is also generally obligated to pay certain real estate taxes, utilities, building operating expenses, insurance, and various other expenses related to properties.

Rental expense under operating lease agreements were as follows (in thousands):

	Fiscal Year
	2016			2015			2014
Minimum rentals	$	40,252		$	36,955		$	33,032
Contingent rentals		1,755			1,827			1,765
Less: sublease rentals		(94	)		(94	)		(94	)
Total	$	41,913		$	38,688		$	34,703

A schedule by year of future minimum rental payments required under operating leases, excluding contingent rent, that have initial or remaining non-cancelable lease terms in excess of one year, as of December 25, 2016, is as follows (in thousands):

Years Ending	Minimum
2017	$	46,035
2018		42,583
2019		38,947
2020		36,818
2021		32,911
Thereafter		96,078
Total minimum payments required*	$	293,372

*	Minimum payments have not been reduced by minimum sublease rentals of $0.2 million due in the future.

Certain leases have outstanding letters of credit in lieu of rent deposits expiring at various dates through September 2017. The letters of credit were $0.6 million in aggregate for each of the years ended December 28, 2014 and December 27, 2015, and $0.7 million in aggregate for the year ended December 25, 2016. Under the credit facility, outstanding letters of credit are subject to an annual fee of 1.50% and reduce the available borrowing to the Company.

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 25, 2016
Postemployment Benefits [Abstract]
Employee Benefit Plan	(11) Employee Benefit Plan The Company sponsors a 401(k) profit sharing plan for all employees who are eligible based upon age and length of service. The Company made matching contributions of $0.3 million for fiscal year 2014 and $0.4 million for fiscal years 2015 and 2016.

Stock Based Compensation

12 Months Ended

Dec. 25, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock Based Compensation

(12) Stock Based Compensation

Stock Based Compensation Granted Under the 2001 and 2004 Equity Incentive Plans and 2013 Long-Term Incentive Plan

Under the 2001 Plan, the Company had 746,749 shares reserved for issuance. In 2007, the Company entered into a Stock Option Agreement (the “Agreement”), which granted a certain key executive 500,000 options of non-voting common stock. In September 2011, the 2001 Plan expired with options outstanding under the plan still available for exercise. As a result of the IPO, all shares of the non-voting common stock converted into voting common stock on a 1:1 basis upon exercise.

On July 31, 2013, the Company’s board of directors approved the adoption of the 2013 Plan, which replaced the 2004 Plan in conjunction with the Company’s IPO. Upon approval of the 2013 Plan, the Company no longer issued awards under the 2004 Plan. The 2004 Plan expired in February 2014, but will continue to govern outstanding awards granted prior to its termination. As of December 25, 2016, there have been 1,646,991 options, 28,240 shares of unrestricted common stock and 88,635 shares of restricted stock units (“RSUs”) granted under the 2013 Plan and 1,099,191 shares are reserved for future issuance.

Under the Plans, the number of shares and exercise price of each option are determined by the committee designated by the Company’s board of directors. The options granted are generally exercisable within a 10-year period from the date of grant. Certain options have been issued to key executives. Options issued and outstanding expire on various dates through the year 2026. The range of exercise prices of options outstanding as of December 25, 2016, is $7.00 to $20.53 per option, and the options vest over a range of immediately to five-year periods.

Activity under the Plans and the Agreement is as follows:

Options	Shares (Thousands)			Weighted Average Exercise Price		Aggregate Intrinsic Value (Thousands)		Weighted Average Remaining Term (Years)
Outstanding—December 29, 2013		5,030		$	9.41	$	78,575		6.31
Granted		318			19.16
Exercised		(586	)		8.67
Canceled		(149	)		11.68
Outstanding—December 28, 2014		4,613		$	10.10	$	12,731		5.62
Granted		565			13.21
Exercised		(576	)		8.30
Canceled		(234	)		13.89
Outstanding—December 27, 2015		4,368		$	10.53	$	9,742		5.10
Granted		369			13.65
Exercised		(536	)		10.77
Canceled		(188	)		14.40
Outstanding—December 25, 2016		4,013		$	10.61	$	13,455		4.78
Vested and expected to vest—December 25, 2016		2,965			9.62	$	10,182		3.54
Exercisable—December 25, 2016		2,989		$	9.61	$	12,675		3.60

The following table reflects the average assumptions utilized in the Black-Scholes option-pricing model to value the options granted for each year:

	2016			2015			2014
Risk-free interest rate		1.7	%		1.9	%		1.3	%
Expected life (years)		7.00			7.00			7.00
Expected dividend yield		—			—			—
Volatility		49.4	%		45.3	%		49.2	%
Weighted average common stock fair value	$	13.65		$	13.21		$	19.16

The risk-free rate is based on U.S. Treasury rates in effect at the time of the grant with a similar duration of the expected life of the options. The expected life of options granted is derived from the average of the vesting period and the term of the option. The Company has not paid dividends to date (with exception to the one-time dividend paid to stockholders prior to the initial public offering) and does not plan to pay dividends in the near future. Beginning October 2015, expected volatility of the options was calculated using the Company’s historical data since its initial public offering. Prior to October 2015, the Company calculated expected volatility of the options based on historical data from selected peer public company restaurants.

During fiscal year 2014, the Company issued 28,240 shares of unrestricted common stock to certain non-employee members of its Board of Directors. The unrestricted stock had a weighted average grant-date share price of $15.29 upon issuance. The Company recorded $0.4 million in stock-based compensation expense, with a corresponding increase to additional paid-in capital, related to the issuance of the common stock.

In May 2015, the Company issued 30,856 shares of “RSUs” to certain non-employee members of its Board of Directors. The RSUs had a grant-date fair value of $14.26 upon issuance. In August 2015, the Company issued 5,221 shares of RSUs to the new non-employee member of its Board of Directors. The RSUs had a grant-date fair value of $11.88 upon issuance. In May 2016, the Company issued 52,558 shares of RSUs to certain non-employee members of its Board of Directors. The RSUs had a grant-date fair value of $13.27 upon issuance. All issued RSUs have a vesting schedule of 50% on the first anniversary of the grant date and 50% on the second anniversary of the grant date.

Stock-based Compensation Expense

In accordance with ASC Topic 718, Compensation—Stock Compensation, stock-based compensation is measured at the grant date, based on the calculated fair value of the award, and is recognized as an expense over the requisite employee service period (generally the vesting period of the grant). The Company recognized $2.5 million, $2.4 million and $3.1 million for the fiscal years 2014, 2015 and 2016, respectively, with a corresponding increase to additional paid-in-capital. Fiscal year 2014 stock-based compensation expense includes $0.4 million related to unrestricted common stock granted during 2014. As of December 25, 2016, the unrecognized stock-based compensation expense was $5.2 million, which will be recognized through fiscal year 2020. The Company records stock-based compensation expense within general and administrative expenses in the consolidated statements of operations.

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References + Details

Quarterly Financial Data (Unaudited)

12 Months Ended

Dec. 25, 2016

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Data (Unaudited)

(13) Quarterly Financial Data (Unaudited)

The unaudited quarterly information includes all normal recurring adjustments that the Company considers necessary for a fair presentation of the information shown. The Company’s quarterly results have been and will continue to be affected by the timing of new shop openings and their associated pre-opening costs. As a result of these and other factors, the financial results for any quarter may not be indicative of the results for any future period.

The following table presents selected unaudited quarterly financial data for periods indicated (in thousands, except per share data):

	Fiscal Year 2016 (1)
	March 27		June 26		September 25		December 25
Total revenues	$	95,955	$	105,036	$	103,782	$	102,358
Income from operations		1,889		5,512		2,842		2,770
Net income attributable to Potbelly Corporation		1,088		3,373		1,795		1,956
Income per share available to common stockholders-basic		0.04		0.13		0.07		0.08
Income per share available to common stockholders-diluted		0.04		0.13		0.07		0.08

	Fiscal Year 2015 (1)
	March 29		June 28		September 27		December 27
Total revenues	$	85,768	$	95,949	$	96,039	$	95,093
Income from operations		948		4,084		2,379		2,018
Net income attributable to Potbelly Corporation		531		2,461		1,401		1,235
Income per share available to common stockholders-basic		0.02		0.09		0.05		0.05
Income per share available to common stockholders-diluted		0.02		0.08		0.05		0.05

(1)	Fiscal years 2016 and 2015 were 52-week years. Each quarter of the fiscal year consists of 13 weeks.

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 25, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	(14) Commitments and Contingencies As previously disclosed in prior reports filed with the SEC, the Company received notice of a potential claim alleging that the Company violated the Fair Labor Standards Act by not paying overtime to its assistant managers, whom the Company has classified as exempt employees. Although the Company has always believed that its assistant managers are properly classified as exempt under both federal and state laws, and have always intended to defend any such lawsuits vigorously, the Company agreed to mediate the matter. On February 20, 2017, the parties entered into a Settlement Agreement and Release whereby participating assistant managers will release the Company from all federal and/or state wage and hour claims in exchange for a gross settlement amount of $1.3 million. As part of the settlement process, a complaint was filed on February 17, 2017 in the Circuit Court of the Fifteenth Judicial Circuit in and for Palm Beach County, Florida, and a motion seeking the Court's preliminary approval of the settlement was filed on February 21, 2017. As of December 25, 2016, the Company recorded a liability of $1.3 million for this matter. The settlement of this action did not have a material adverse effect on our financial position or results of operations and cash flows. The Company is subject to legal proceedings, claims and liabilities, such as employment-related claims and slip and fall cases, which arise in the ordinary course of business and are generally covered by insurance. In the opinion of management, the amount of ultimate liability with respect to those actions should not have a material adverse impact on the Company’s financial position or results of operations and cash flows.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 25, 2016

Accounting Policies [Abstract]

Principles of Consolidation

(a) Principles of Consolidation

Reporting Period

(b) Reporting Period

Segment Reporting

Use of Estimates

(d) Use of Estimates

Fair Value Measurements

(e) Fair Value Measurements

•

Level 1—Quoted prices in active markets for identical assets or liabilities.

•

Financial Instruments

(f) Financial Instruments

Cash and Cash Equivalents

(g) Cash and Cash Equivalents

Accounts Receivable, net

(h) Accounts Receivable, net

Inventories

(i) Inventories

Property and Equipment

(j) Property and Equipment

Intangible Assets

(k) Intangible Assets

Pre-opening Costs

(l) Pre-opening Costs

Advertising Expenses

(m) Advertising Expenses

Income Taxes

(n) Income Taxes

Stock-Based Compensation

(o) Stock-Based Compensation

Leases

(p) Leases

Revenue Recognition

(q) Revenue Recognition

Recent Accounting Pronouncements

(r) Recent Accounting Pronouncements

Commitments and Contingencies

(s) Commitments and Contingencies

Earnings per Share (Tables)

12 Months Ended

Dec. 25, 2016

Earnings Per Share [Abstract]

Schedule of the Calculation of Weighted Average Common Shares Outstanding for Basic and Diluted Earnings per Share Available to Common Stockholders

	Fiscal Year
	2016		2015		2014
Net income attributable to Potbelly Corporation	$	8,212	$	5,628	$	4,358
Weighted average common shares outstanding-basic		25,623,809		28,002,005		29,209,298
Plus: Effect of potential stock options exercise		549,578		577,156		949,142
Plus: Effect of potential warrant exercise		57,980		55,235		116,621
Weighted average common shares outstanding-diluted		26,231,367		28,634,396		30,275,061
Income per share available to common stockholders-basic	$	0.32	$	0.20	$	0.15
Income per share available to common stockholders-diluted	$	0.31	$	0.20	$	0.14
Potentially dilutive shares that are considered anti-dilutive:
Common share options		1,164,047		898,966		622,879
Warrants		—		—		—

Property and Equipment (Tables)

12 Months Ended

Dec. 25, 2016

Property Plant And Equipment [Abstract]

Components of Property and Equipment, Net

Property and equipment, net consisted of the following (in thousands):

	December 25,			December 27,
	2016			2015
Leasehold improvements	$	170,196		$	157,556
Machinery and equipment		47,668			42,840
Furniture and fixtures		32,561			28,605
Computer equipment and software		23,162			20,077
Construction in progress		5,601			3,074
		279,188			252,152
Less: Accumulated depreciation		(172,114	)		(154,718	)
	$	107,074		$	97,434

Accrued Expenses (Tables)

12 Months Ended

Dec. 25, 2016

Accrued Liabilities Current [Abstract]

Summary of Accrued Expenses

Accrued expenses consisted of the following (in thousands):

	December 25,		December 27,
	2016		2015
Accrued labor and related expenses	$	6,120	$	7,482
Deferred gift card revenue		2,292		1,843
Accrued occupancy expenses		1,538		672
Deferred rent—current		706		813
Accrued corporate and shop expenses		2,255		1,961
Accrued utilities		1,094		1,035
Accrued sales and use tax		1,857		1,820
Accrued construction		2,329		2,271
Accrued contract termination costs (a)		28		21
Accrued legal and professional fees		1,756		136
Accrued other		3,107		1,223
Total	$	23,082	$	19,277

(a)	The Company incurs expenses associated with exit activity for certain signed lease agreements, which are recognized in general and administrative expenses. Accrued contract termination costs consisted of the following (in thousands):

	December 25,			December 27,
	2016			2015
Accrued contract termination costs—beginning balance	$	21		$	801
Contract termination costs incurred		24			—
Contract termination costs settled and paid		(17	)		(780	)
Accrued contract termination costs—ending balance	$	28		$	21

Summary of Accrued Contract Termination Costs

Accrued contract termination costs consisted of the following (in thousands):

	December 25,			December 27,
	2016			2015
Accrued contract termination costs—beginning balance	$	21		$	801
Contract termination costs incurred		24			—
Contract termination costs settled and paid		(17	)		(780	)
Accrued contract termination costs—ending balance	$	28		$	21

Income Taxes (Tables)

12 Months Ended

Dec. 25, 2016

Income Tax Disclosure [Abstract]

Schedule of Income Before Income Taxes

Income before income taxes for the Company’s domestic and foreign operations was as follows (in thousands):

	Fiscal Year
	2016		2015		2014
Domestic operations	$	12,411	$	8,660	$	6,627
Foreign operations		468		548		465
Total	$	12,879	$	9,208	$	7,092

Components of Income Tax Expense

Income tax expense consisted of the following (in thousands):

	Fiscal Year
	2016			2015			2014
Federal:
Current	$	4,652		$	2,450		$	2,386
Deferred		(1,386	)		209			(467	)
		3,266			2,659			1,919
State and Local:
Current		1,426			1,047			622
Deferred		(273	)		(281	)		178
		1,153			766			800
Foreign:
Current		24			41			29
Deferred		—			—			—
		24			41			29
Income tax expense	$	4,443		$	3,466		$	2,748

Reconciliation of Differences Between Federal Statutory and Effective Income Tax Rate

Income tax expense differed from the amounts computed by applying the U.S. federal income tax rates to income before income taxes as a result of the following (in thousands):

	Fiscal Year
	2016			2015			2014
Computed “expected” tax expense	$	4,508		$	3,223		$	2,411
Increase (reduction) resulting from:
Minority interest		(89	)		(45	)		—
Permanent differences		131			51			97
State and local income taxes, net of federal income tax effect		673			533			460
FICA and other tax credits		(556	)		(392	)		(222	)
Rate change and true-ups (a)		(224	)		164			2
Change in valuation allowance		—			(68	)		—
	$	4,443		$	3,466		$	2,748

(a)	The $(224) of rate changes and true-ups relates primarily to a favorable provision-to-return adjustment related to WOTC credits.

Schedule of Deferred Tax Assets and Liabilities

	December 25,			December 27,
	2016			2015
Deferred tax assets:
Accrued liabilities	$	1,848		$	2,074
Deferred revenue on gift certificates and gift cards		323			141
Stock-based compensation		8,104			8,261
Property and equipment depreciation		6,293			5,805
Deferred rent and start-up amortization		5,656			4,650
Other timing differences		234			273
FICA and other tax credits		—			43
Total deferred tax assets		22,458			21,247
Less: valuation allowance		—			—
Net deferred tax assets		22,458			21,247
Deferred tax liabilities:
Prepaids		(635	)		(547	)
Intangible asset		(1,351	)		(1,226	)
Smallwares		(801	)		(733	)
Other timing differences		(261	)		(302	)
Total gross deferred tax liabilities		(3,048	)		(2,808	)
Net deferred tax assets	$	19,410		$	18,439

Operating Leases (Tables)

12 Months Ended

Dec. 25, 2016

Leases [Abstract]

Schedule Of Rental Expenses Under Operating Leases

Rental expense under operating lease agreements were as follows (in thousands):

	Fiscal Year
	2016			2015			2014
Minimum rentals	$	40,252		$	36,955		$	33,032
Contingent rentals		1,755			1,827			1,765
Less: sublease rentals		(94	)		(94	)		(94	)
Total	$	41,913		$	38,688		$	34,703

Schedule of Future Minimum Rental Payments Under Operating Leases

Years Ending	Minimum
2017	$	46,035
2018		42,583
2019		38,947
2020		36,818
2021		32,911
Thereafter		96,078
Total minimum payments required*	$	293,372

*	Minimum payments have not been reduced by minimum sublease rentals of $0.2 million due in the future.

Stock Based Compensation (Tables)

12 Months Ended

Dec. 25, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Activity Under Plans and Agreement

Activity under the Plans and the Agreement is as follows:

Options	Shares (Thousands)			Weighted Average Exercise Price		Aggregate Intrinsic Value (Thousands)		Weighted Average Remaining Term (Years)
Outstanding—December 29, 2013		5,030		$	9.41	$	78,575		6.31
Granted		318			19.16
Exercised		(586	)		8.67
Canceled		(149	)		11.68
Outstanding—December 28, 2014		4,613		$	10.10	$	12,731		5.62
Granted		565			13.21
Exercised		(576	)		8.30
Canceled		(234	)		13.89
Outstanding—December 27, 2015		4,368		$	10.53	$	9,742		5.10
Granted		369			13.65
Exercised		(536	)		10.77
Canceled		(188	)		14.40
Outstanding—December 25, 2016		4,013		$	10.61	$	13,455		4.78
Vested and expected to vest—December 25, 2016		2,965			9.62	$	10,182		3.54
Exercisable—December 25, 2016		2,989		$	9.61	$	12,675		3.60

Schedule of Average Assumptions to Value Options

The following table reflects the average assumptions utilized in the Black-Scholes option-pricing model to value the options granted for each year:

	2016			2015			2014
Risk-free interest rate		1.7	%		1.9	%		1.3	%
Expected life (years)		7.00			7.00			7.00
Expected dividend yield		—			—			—
Volatility		49.4	%		45.3	%		49.2	%
Weighted average common stock fair value	$	13.65		$	13.21		$	19.16

Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 25, 2016

Quarterly Financial Information Disclosure [Abstract]

Summary of Unaudited Quarterly Financial Data

The following table presents selected unaudited quarterly financial data for periods indicated (in thousands, except per share data):

	Fiscal Year 2016 (1)
	March 27		June 26		September 25		December 25
Total revenues	$	95,955	$	105,036	$	103,782	$	102,358
Income from operations		1,889		5,512		2,842		2,770
Net income attributable to Potbelly Corporation		1,088		3,373		1,795		1,956
Income per share available to common stockholders-basic		0.04		0.13		0.07		0.08
Income per share available to common stockholders-diluted		0.04		0.13		0.07		0.08

	Fiscal Year 2015 (1)
	March 29		June 28		September 27		December 27
Total revenues	$	85,768	$	95,949	$	96,039	$	95,093
Income from operations		948		4,084		2,379		2,018
Net income attributable to Potbelly Corporation		531		2,461		1,401		1,235
Income per share available to common stockholders-basic		0.02		0.09		0.05		0.05
Income per share available to common stockholders-diluted		0.02		0.08		0.05		0.05

(1)	Fiscal years 2016 and 2015 were 52-week years. Each quarter of the fiscal year consists of 13 weeks.

Organization and Other Matters - Additional Information (Detail)			1 Months Ended		12 Months Ended
	Oct. 09, 2013 USD ($) shares	Oct. 08, 2013 USD ($)	Apr. 30, 2016 USD ($) Store	Jul. 31, 2015 USD ($) Store	Dec. 25, 2016 USD ($) State	Dec. 27, 2015 USD ($)	Dec. 28, 2014 USD ($)
Nature Of Business And Basis Of Presentation [Line Items]
Number of sandwich works and shops operation states \| State					29
Purchase price of transitioned franchise shop			$ 1,100,000	$ 300,000	$ 1,108,000	$ 333,000
Goodwill					2,222,000	1,428,000
Cash dividend paid from proceeds from IPO		$ 49,900,000
Public offering proceeds used for repayments of debt		$ 14,000,000
Net Proceeds to repurchase of common stock					$ 22,321,000	$ 39,754,000	$ 10,246,000
IPO [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Public offering shares of common stock \| shares	8,625,000
Share sold by company \| shares	8,474,869
Net proceeds from IPO	$ 108,800,000
IPO [Member] \| Underwritten Public Offering [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Public offering shares of common stock \| shares	1,125,000
IPO [Member] \| Shareholders' Equity [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Share sold by stock holders through public offering \| shares	150,131
Company-Operated Shops [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Number of franchise shop transitioned \| Store			1	1
Franchise-Operated Shops [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Goodwill			$ 800,000	$ 0

Summary of Significant Accounting Policies - Additional Information (Detail)		12 Months Ended
	Feb. 21, 2017 USD ($)	Dec. 25, 2016 USD ($) Subsidiary JointVenture Segment	Dec. 27, 2015 USD ($)	Dec. 28, 2014 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of wholly owned subsidiaries \| Subsidiary		8
Number of joint ventures \| JointVenture		5
Number of operating segments \| Segment		1
Number of reportable segments \| Segment		1
Credit card receivables		$ 1,600,000	$ 2,000,000
Capitalized costs		600,000	600,000	$ 900,000
Impairment charges		4,000,000	3,400,000	2,900,000
Recognized impairment for intangible assets		0	0	0
Advertising expenses		3,000,000	2,900,000	2,200,000
Initial franchise fee		400,000	400,000	300,000
Royalty fees revenue		1,900,000	1,500,000	$ 1,200,000
Company recorded liability		1,300,000
Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Gross settlement amount	$ 1,300,000
ASU No. 2016-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Effect of increasing income tax expense		700,000
Initial Franchise Fees [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred revenue		700,000	500,000
Franchise Development Agreement [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred revenue		$ 400,000	$ 400,000
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Ownership interest rate		51.00%
Estimated period of time between Company's possession of leased space and shop opening date		2 months
Minimum [Member] \| Computer Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life		3 years
Minimum [Member] \| Furniture and Fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life		3 years
Minimum [Member] \| Computer Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life		3 years
Minimum [Member] \| Machinery and Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life		3 years
Minimum [Member] \| Leasehold Improvements [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life		10 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Ownership interest rate		80.00%
Estimated period of time between Company's possession of leased space and shop opening date		3 months
Maximum [Member] \| Computer Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life		5 years
Maximum [Member] \| Furniture and Fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life		5 years
Maximum [Member] \| Computer Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life		5 years
Maximum [Member] \| Machinery and Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life		5 years
Maximum [Member] \| Leasehold Improvements [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life		15 years

Fair Value Measurement - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Fair Value Disclosures [Abstract]
Impairment charges	$ 4.0	$ 3.4	$ 2.9

Earnings Per Share - Schedule of the Calculation of Weighted Average Common Shares Outstanding for Basic and Diluted Earnings per Share Available to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 25, 2016	Sep. 25, 2016	Jun. 26, 2016	Mar. 27, 2016	Dec. 27, 2015	Sep. 27, 2015	Jun. 28, 2015	Mar. 29, 2015	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income attributable to Potbelly Corporation	$ 1,956	$ 1,795	$ 3,373	$ 1,088	$ 1,235	$ 1,401	$ 2,461	$ 531	$ 8,212	$ 5,628	$ 4,358
Weighted average common shares outstanding-basic									25,623,809	28,002,005	29,209,298
Plus: Effect of potential stock options exercise									549,578	577,156	949,142
Plus: Effect of potential warrant exercise									57,980	55,235	116,621
Weighted average common shares outstanding-diluted									26,231,367	28,634,396	30,275,061
Income per share available to common stockholders-basic	$ 0.08	$ 0.07	$ 0.13	$ 0.04	$ 0.05	$ 0.05	$ 0.09	$ 0.02	$ 0.32	$ 0.20	$ 0.15
Income per share available to common stockholders-diluted	$ 0.08	$ 0.07	$ 0.13	$ 0.04	$ 0.05	$ 0.05	$ 0.08	$ 0.02	$ 0.31	$ 0.20	$ 0.14
Common Share Options [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Potentially dilutive shares that are considered anti-dilutive									1,164,047	898,966	622,879
Warrants [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Potentially dilutive shares that are considered anti-dilutive									0	0	0

Property and Equipment - Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 25, 2016	Dec. 27, 2015
Property Plant And Equipment [Abstract]
Leasehold improvements	$ 170,196	$ 157,556
Machinery and equipment	47,668	42,840
Furniture and fixtures	32,561	28,605
Computer equipment and software	23,162	20,077
Construction in progress	5,601	3,074
Property and equipment, gross	279,188	252,152
Less: Accumulated depreciation	(172,114)	(154,718)
Property and equipment, net	$ 107,074	$ 97,434

Accrued Expenses - Summary of Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Accrued Liabilities And Other Liabilities [Abstract]
Accrued labor and related expenses	$ 6,120	$ 7,482
Deferred gift card revenue	2,292	1,843
Accrued occupancy expenses	1,538	672
Deferred rent—current	706	813
Accrued corporate and shop expenses	2,255	1,961
Accrued utilities	1,094	1,035
Accrued sales and use tax	1,857	1,820
Accrued construction	2,329	2,271
Accrued contract termination costs	28	21	$ 801
Accrued legal and professional fees	1,756	136
Accrued other	3,107	1,223
Total	$ 23,082	$ 19,277

Accrued Expenses - Summary of Accrued Contract Termination Costs (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015
Accrued Liabilities And Other Liabilities [Abstract]
Accrued contract termination costs—beginning balance	$ 21	$ 801
Contract termination costs incurred	24
Contract termination costs settled and paid	(17)	(780)
Accrued contract termination costs—ending balance	$ 28	$ 21

Income Taxes - Schedule of Income Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Income Tax Disclosure [Abstract]
Domestic operations	$ 12,411	$ 8,660	$ 6,627
Foreign operations	468	548	465
Income before income taxes	$ 12,879	$ 9,208	$ 7,092

Income Taxes - Components of Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Income Tax Disclosure [Abstract]
Federal, Current	$ 4,652	$ 2,450	$ 2,386
Federal, Deferred	(1,386)	209	(467)
Federal, Total	3,266	2,659	1,919
State and Local, Current	1,426	1,047	622
State and Local, Deferred	(273)	(281)	178
State and Local, Total	1,153	766	800
Foreign, Current	24	41	29
Foreign, Total	24	41	29
Income tax expense	$ 4,443	$ 3,466	$ 2,748

Income Taxes - Reconciliation of Differences Between Federal Statutory and Effective Income Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Income Tax Disclosure [Abstract]
Computed “expected” tax expense	$ 4,508	$ 3,223	$ 2,411
Minority interest	(89)	(45)
Permanent differences	131	51	97
State and local income taxes, net of federal income tax effect	673	533	460
FICA and other tax credits	(556)	(392)	(222)
Rate change and true-ups	(224)	164	2
Change in valuation allowance		(68)
Income tax expense	$ 4,443	$ 3,466	$ 2,748

Income Taxes - Reconciliation of Differences Between Federal Statutory and Effective Income Tax Rate (Parenthetical) (Detail) $ in Thousands	12 Months Ended
	Dec. 25, 2016 USD ($)
Income Tax Disclosure [Abstract]
Favorable provision-to-return adjustment related to WOTC credits	$ (224)

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 25, 2016	Dec. 27, 2015
Deferred tax assets:
Accrued liabilities	$ 1,848	$ 2,074
Deferred revenue on gift certificates and gift cards	323	141
Stock-based compensation	8,104	8,261
Property and equipment depreciation	6,293	5,805
Deferred rent and start-up amortization	5,656	4,650
Other timing differences	234	273
FICA and other tax credits		43
Total deferred tax assets	22,458	21,247
Net deferred tax assets	22,458	21,247
Deferred tax liabilities:
Prepaids	(635)	(547)
Intangible asset	(1,351)	(1,226)
Smallwares	(801)	(733)
Other timing differences	(261)	(302)
Total gross deferred tax liabilities	(3,048)	(2,808)
Net deferred tax assets	$ 19,410	$ 18,439

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015
Income Tax [Line Items]
Change in valuation allowance		$ (68,000)
Unrecognized tax benefits, income tax penalties and interest accrued	$ 0	0
Valuation Allowance Tax Credit Carryforward
Income Tax [Line Items]
Change in valuation allowance	$ 0	$ 0

Long-term Debt - Additional Information (Detail) - USD ($)		12 Months Ended
	Dec. 09, 2015	Dec. 25, 2016	Dec. 28, 2014
J P Morgan Chase Bank N A [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Percentage of commitment fees based on credit facility		0.125%
J P Morgan Chase Bank N A [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Percentage of commitment fees based on credit facility		0.20%
J P Morgan Chase Bank N A [Member] \| Senior Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility agreement term period	5 years
Revolving credit facility agreement expiration date		Nov. 30, 2020
Credit facility, Maximum borrowing capacity	$ 50,000,000
Credit facility, possible future maximum borrowing capacity	$ 75,000,000
Credit facility outstanding amount		$ 0
Credit facility, remaining borrowing capacity		$ 49,300,000
J P Morgan Chase Bank N A [Member] \| Senior Credit Facility [Member] \| LIBOR [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.00%
J P Morgan Chase Bank N A [Member] \| Senior Credit Facility [Member] \| LIBOR [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.75%
J P Morgan Chase Bank N A [Member] \| Senior Credit Facility [Member] \| Prime Rate [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.00%
J P Morgan Chase Bank N A [Member] \| Senior Credit Facility [Member] \| Prime Rate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.50%
Note Payable [Member]
Debt Instrument [Line Items]
Interest rate on notes payable under effective interest rate method			6.20%
Interest expense on note payable			$ 100,000
Final repayment of interest and principal		Apr. 01, 2015

Capital Stock and Warrants - Additional Information (Detail) - USD ($)		12 Months Ended
	Dec. 29, 2013	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014	Sep. 08, 2016	Sep. 08, 2015
Equity [Abstract]
Capital stock, authorized		210,000,000	210,000,000
Common stock, authorized		200,000,000	200,000,000
Preferred stock, authorized		10,000,000	10,000,000
Common stock, issued		30,892,539	30,338,171
Common stock, outstanding		25,139,127	26,304,261
Stock repurchase program, authorized amount					$ 30,000,000	$ 35,000,000
Common stock shares repurchased		1,719,502
Common stock repurchased value		$ 22,321,000	$ 39,754,000	$ 10,246,000
Remaining dollar value of authorization under the share repurchase program		$ 27,700,000
Company warrants outstanding		241,704	241,704
Modification of warrants issued	241,704
Expiration date of warrants		5 years
Recognized stock compensation expense		$ 100,000

Operating Leases - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 25, 2016 USD ($) Option	Dec. 27, 2015 USD ($)	Dec. 28, 2014 USD ($)
Operating Leased Assets [Line Items]
Initial operating lease period	10 years
Number of renewal options under operating leases \| Option	2
Operating lease rent increment term	5 years
Letters of credit in lieu of rent deposits \| $	$ 0.7	$ 0.6	$ 0.6
Letters of credit annual fee percentage	1.50%
Minimum [Member]
Operating Leased Assets [Line Items]
Operating lease period for expiration or renewal	2017
Maximum [Member]
Operating Leased Assets [Line Items]
Operating lease period for expiration or renewal	2029

Operating Leases - Schedule of Rental Expenses Under Operating Leases (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Operating Leases Rent Expense [Abstract]
Minimum rentals	$ 40,252	$ 36,955	$ 33,032
Contingent rentals	1,755	1,827	1,765
Less: sublease rentals	(94)	(94)	(94)
Total	$ 41,913	$ 38,688	$ 34,703

- Definition

The increases or decreases in lease payments that result from changes occurring after the inception of the lease in the factors (other than the passage of time) on which lease payments are based, except that any escalation of minimum lease payments relating to increases in construction or acquisition cost of the leased property or for increases in some measure of cost or value during the construction or preconstruction period, are excluded from contingent rentals. Contingent rentals also may include amounts for which the triggering events have not yet occurred or the specified targets for which have not yet been achieved (such as sales based percentage rent), but which events are considered probable of occurring or which specified targets are considered probable of being achieved.

+ References + Details

Operating Leases - Schedule of Future Minimum Rental Payments Under Operating Leases (Detail) $ in Thousands	Dec. 25, 2016 USD ($)
Leases [Abstract]
2017	$ 46,035
2018	42,583
2019	38,947
2020	36,818
2021	32,911
Thereafter	96,078
Total minimum payments required	$ 293,372

Operating Leases - Schedule of Future Minimum Rental Payments Under Operating Leases (Parenthetical) (Detail) $ in Millions	Dec. 25, 2016 USD ($)
Leases [Abstract]
Minimum sublease rentals due in future	$ 0.2

Employee Benefit Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Defined Benefit Plans And Other Postretirement Benefit Plans Disclosures [Abstract]
Contributions made to profit sharing plan	$ 0.4	$ 0.4	$ 0.3

Stock Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	May 31, 2016	Aug. 31, 2015	May 31, 2015	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-voting Common stock conversion basis ratio				100.00%
Weighted average share value of unrestricted common stock				$ 100
Recognized stock-based compensation expense				3,057	$ 2,399	$ 2,543
Unrecognized stock compensation expense				$ 5,200
Unrecognized stock compensation expense, recognition period				Through 2020
Non-Employee Board Of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of unrestricted common stock						28,240
Weighted average grant-date share price						$ 15.29
Weighted average share value of unrestricted common stock						$ 400
Restricted Stock Units (RSUs) [Member] \| Non-Employee Board Of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units issued	52,558	5,221	30,856
Restricted stock units issued, grant-date fair value	$ 13.27	$ 11.88	$ 14.26
Restricted Stock Units (RSUs) [Member] \| First Anniversary [Member] \| Non-Employee Board Of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	50.00%	50.00%	50.00%
Restricted Stock Units (RSUs) [Member] \| Second Anniversary [Member] \| Non-Employee Board Of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	50.00%	50.00%	50.00%
Unrestricted Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized stock-based compensation expense						$ 400
2001 Equity Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance				746,749
2001 Equity Incentive Plans [Member] \| Non-Voting Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock issued to key executive				500,000
2013 Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance				1,099,191
Options granted				1,646,991
2013 Long-Term Incentive Plan [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units issued				88,635
2013 Long-Term Incentive Plan [Member] \| Unrestricted Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of unrestricted common stock				28,240
2001 and 2004 Equity Incentive Plans and 2013 Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of options outstanding, lower limit				$ 7.00
Exercise price of options outstanding, higher limit				$ 20.53
2001 and 2004 Equity Incentive Plans and 2013 Long-Term Incentive Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercisable period from the date of grant				10 years
Options issued and outstanding, last expiration date				Dec. 31, 2026
Options vesting period				5 years

Stock Based Compensation - Summary of Activity Under Plans and Agreement (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014	Dec. 29, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options Outstanding shares, Beginning balance	4,368	4,613	5,030
Options, Granted	369	565	318
Options, Exercised	(536)	(576)	(586)
Options, Canceled	(188)	(234)	(149)
Options Outstanding shares, Ending balance	4,013	4,368	4,613	5,030
Options Outstanding shares, Vested and expected to vest	2,965
Options Outstanding shares, Exercisable	2,989
Options outstanding weighted average exercise price, Beginning balance	$ 10.53	$ 10.10	$ 9.41
Options, Weighted Average Exercise Price, Granted	13.65	13.21	19.16
Options, Weighted Average Exercise Price, Exercised	10.77	8.30	8.67
Options, Weighted Average Exercise Price, Canceled	14.40	13.89	11.68
Options outstanding weighted average exercise price, Ending balance	10.61	$ 10.53	$ 10.10	$ 9.41
Options outstanding weighted average exercise price, vested and expected to vest	9.62
Options outstanding weighted average exercise price, Exercisable	$ 9.61
Options Outstanding Aggregate Intrinsic value	$ 13,455	$ 9,742	$ 12,731	$ 78,575
Options Vested and Expected to Vest Aggregate Intrinsic Value	10,182
Options Exercisable Aggregate Intrinsic Value	$ 12,675
Option Outstanding Weighted Average Remaining Term	4 years 9 months 11 days	5 years 1 month 6 days	5 years 7 months 13 days	6 years 3 months 22 days
Options Vested and Expected to Vest Weighted Average Remaining Term	3 years 6 months 15 days
Options Exercisable Weighted Average Remaining Term	3 years 7 months 6 days

Stock Based Compensation - Schedule of Average Assumptions to Value Options (Detail) - $ / shares	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]
Risk-free interest rate	1.70%	1.90%	1.30%
Expected life (years)	7 years	7 years	7 years
Expected dividend yield	0.00%	0.00%	0.00%
Volatility	49.40%	45.30%	49.20%
Weighted average common stock fair value	$ 13.65	$ 13.21	$ 19.16

Quarterly Financial Data (Unaudited) - Summary of Unaudited Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 25, 2016	Sep. 25, 2016	Jun. 26, 2016	Mar. 27, 2016	Dec. 27, 2015	Sep. 27, 2015	Jun. 28, 2015	Mar. 29, 2015	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 102,358	$ 103,782	$ 105,036	$ 95,955	$ 95,093	$ 96,039	$ 95,949	$ 85,768	$ 407,131	$ 372,849	$ 326,979
Income from operations	2,770	2,842	5,512	1,889	2,018	2,379	4,084	948	13,013	9,429	7,271
Net income attributable to Potbelly Corporation	$ 1,956	$ 1,795	$ 3,373	$ 1,088	$ 1,235	$ 1,401	$ 2,461	$ 531	$ 8,212	$ 5,628	$ 4,358
Income per share available to common stockholders-basic	$ 0.08	$ 0.07	$ 0.13	$ 0.04	$ 0.05	$ 0.05	$ 0.09	$ 0.02	$ 0.32	$ 0.20	$ 0.15
Income per share available to common stockholders-diluted	$ 0.08	$ 0.07	$ 0.13	$ 0.04	$ 0.05	$ 0.05	$ 0.08	$ 0.02	$ 0.31	$ 0.20	$ 0.14

Commitment and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Feb. 21, 2017	Dec. 25, 2016
Loss Contingencies [Line Items]
Company recorded liability		$ 1.3
Subsequent Event [Member]
Loss Contingencies [Line Items]
Gross settlement amount	$ 1.3