Potbelly (PBPB) 10-Q 5 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 28, 2020	Jul. 26, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 28, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	PBPB
Security Exchange Name	NASDAQ
Entity Registrant Name	Potbelly Corporation
Entity Central Index Key	0001195734
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-27
Entity Filer Category	Accelerated Filer
Entity Shell Company	false
Entity Bankruptcy Proceedings, Reporting Current	true
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		23,899,000
Entity File Number	001-36104
Entity Tax Identification Number	36-4466837
Entity Address, Address Line One	111 N. Canal Street
Entity Address, Address Line Two	Suite 850
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Incorporation, State or Country Code	DE
Entity Address, Postal Zip Code	60606
City Area Code	312
Local Phone Number	951-0600
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 29, 2019
Current assets
Cash and cash equivalents	$ 29,092	$ 18,806
Accounts receivable, net of allowances of $58 and $202 as of June 28, 2020 and December 29, 2019, respectively	3,357	4,257
Inventories	2,823	3,473
Prepaid expenses and other current assets	8,448	5,687
Total current assets	43,720	32,223
Property and equipment, net	68,492	79,032
Right-of-use assets for operating leases	205,131	211,988
Indefinite-lived intangible assets	3,404	3,404
Goodwill	2,222	2,222
Deferred expenses, net and other assets	4,303	4,010
Total assets	327,272	332,879
Current liabilities
Accounts payable	6,691	3,886
Accrued expenses	18,041	20,398
Short-term operating lease liabilities	38,653	29,319
Accrued income taxes	171	171
Total current liabilities	63,556	53,774
Debt from revolving credit facility	23,086
Long-term operating lease liabilities	201,754	206,726
Other long-term liabilities	4,223	3,210
Total liabilities	292,619	263,710
Commitments and contingencies (Note 10)
Equity
Common stock, $0.01 par value—authorized 200,000 shares; outstanding 23,898 and 23,638 shares as of June 28, 2020 and December 29, 2019, respectively	334	331
Additional paid-in-capital	436,536	435,278
Treasury stock, held at cost, 9,490 and 9,465 shares as of June 28, 2020, and December 29, 2019, respectively	(112,757)	(112,680)
Accumulated deficit	(289,638)	(254,081)
Total stockholders’ equity	34,475	68,848
Non-controlling interest	178	321
Total equity	34,653	69,169
Total liabilities and equity	$ 327,272	$ 332,879

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 29, 2019
Statement Of Financial Position [Abstract]
Allowances on accounts receivable	$ 58	$ 202
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	200,000,000	200,000,000
Common stock, outstanding	23,898,000	23,638,000
Treasury stock, shares	9,490,000	9,465,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Revenues
Total revenues	$ 56,162	$ 105,630	$ 143,752	$ 203,717
Sandwich shop operating expenses
Labor and related expenses	21,884	32,114	52,281	64,087
Occupancy expenses	14,649	15,230	29,677	29,607
Other operating expenses	10,990	11,816	23,755	23,961
General and administrative expenses	8,164	13,843	18,898	26,552
Depreciation expense	4,955	5,585	10,411	11,121
Pre-opening costs			64	10
Impairment and loss on disposal of property and equipment	1,299	246	7,256	328
Total expenses	78,049	107,098	182,624	209,908
Loss from operations	(21,887)	(1,468)	(38,872)	(6,191)
Interest expense	388	35	462	67
Loss before income taxes	(22,275)	(1,503)	(39,334)	(6,258)
Income tax expense (benefit)	41	246	(3,668)	13,865
Net loss	(22,316)	(1,749)	(35,666)	(20,123)
Net income (loss) attributable to non-controlling interest	(100)	117	(114)	182
Net loss attributable to Potbelly Corporation	$ (22,216)	$ (1,866)	$ (35,552)	$ (20,305)
Net loss per common share attributable to common stockholders:
Basic	$ (0.93)	$ (0.08)	$ (1.50)	$ (0.85)
Diluted	$ (0.93)	$ (0.08)	$ (1.50)	$ (0.85)
Weighted average shares outstanding:
Basic	23,773	23,908	23,709	24,021
Diluted	23,773	23,908	23,709	24,021
Product [Member]
Revenues
Total revenues	$ 55,863	$ 104,801	$ 142,824	$ 202,059
Sandwich shop operating expenses
Cost of goods sold, excluding depreciation	16,108	28,264	40,282	54,242
Franchise Royalties And Fees [Member]
Revenues
Total revenues	$ 299	$ 829	$ 928	$ 1,658

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]Revision of Prior Period, Adjustment [Member]	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in-Capital [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member]Cumulative Effect, Period of Adoption, Adjustment [Member]Revision of Prior Period, Adjustment [Member]	Non-Controlling Interest [Member]
Beginning balance at Dec. 30, 2018	$ 95,533		$ 330	$ (108,372)	$ 432,771	$ (229,558)		$ 362
Beginning balance, common shares at Dec. 30, 2018			24,143
Cumulative impact (ASU 2016-02 (Topic 842) [Member]) at Dec. 30, 2018		$ (531)					$ (531)
Net income (loss)	(20,123)					(20,305)		182
Stock-based compensation plans	173		$ 1		172
Stock-based compensation plans, shares			116
Repurchases of common stock	(3,467)			(3,467)
Repurchases of common stock, shares			(486)
Distributions to non-controlling interest	(177)							(177)
Contributions from non-controlling interest	39							39
Treasury shares used for stock-based plans	(35)			(35)
Treasury shares used for stock-based plans, shares			(5)
Stock-based compensation expense	1,464				1,464
Ending balance at Jun. 30, 2019	72,876		$ 331	(111,874)	434,407	(250,394)		406
Ending balance, common shares at Jun. 30, 2019			23,768
Beginning balance at Mar. 31, 2019	76,088		$ 330	(109,541)	433,400	(248,528)		427
Beginning balance, common shares at Mar. 31, 2019			24,038
Net income (loss)	(1,749)					(1,866)		117
Stock-based compensation plans	3		$ 1		2
Stock-based compensation plans, shares			83
Repurchases of common stock	(2,323)			(2,323)
Repurchases of common stock, shares			(351)
Distributions to non-controlling interest	(177)							(177)
Contributions from non-controlling interest	39							39
Treasury shares used for stock-based plans	(10)			(10)
Treasury shares used for stock-based plans, shares			(2)
Stock-based compensation expense	1,005				1,005
Ending balance at Jun. 30, 2019	72,876		$ 331	(111,874)	434,407	(250,394)		406
Ending balance, common shares at Jun. 30, 2019			23,768
Beginning balance at Dec. 29, 2019	$ 69,169		$ 331	(112,680)	435,278	(254,081)		321
Beginning balance, common shares at Dec. 29, 2019	23,638		23,638
Cumulative impact at Dec. 29, 2019	$ (254,081)
Cumulative impact (ASU 2016-13 (Topic 326) [Member]) at Dec. 29, 2019		$ (5)					$ (5)
Net income (loss)	(35,666)					(35,552)		(114)
Stock-based compensation plans			$ 2		(2)
Stock-based compensation plans, shares			154
Shares issued for proxy-related expenses	389		$ 1		388
Shares issued for proxy-related expenses, shares			130
Distributions to non-controlling interest	(172)							(172)
Contributions from non-controlling interest	143							143
Treasury shares used for stock-based plans	(77)			(77)
Treasury shares used for stock-based plans, shares			(24)
Stock-based compensation expense	872				872
Ending balance at Jun. 28, 2020	$ 34,653		$ 334	(112,757)	436,536	(289,638)		178
Ending balance, common shares at Jun. 28, 2020	23,898		23,898
Beginning balance at Mar. 29, 2020	$ 56,204		$ 331	(112,751)	435,768	(267,422)		278
Beginning balance, common shares at Mar. 29, 2020			23,684
Net income (loss)	(22,316)					(22,216)		(100)
Stock-based compensation plans			$ 2		(2)
Stock-based compensation plans, shares			86
Shares issued for proxy-related expenses	389		$ 1		388
Shares issued for proxy-related expenses, shares			130
Treasury shares used for stock-based plans	(6)			(6)
Treasury shares used for stock-based plans, shares			(2)
Stock-based compensation expense	382				382
Ending balance at Jun. 28, 2020	$ 34,653		$ 334	$ (112,757)	$ 436,536	$ (289,638)		$ 178
Ending balance, common shares at Jun. 28, 2020	23,898		23,898

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019
ASU 2016-02 (Topic 842) [Member]
Cumulative impact tax	$ 2	$ 196

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income (loss)	$ (35,666)	$ (20,123)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation expense	10,411	11,121
Noncash lease expense	14,333	13,826
Deferred income tax	9	13,790
Stock-based compensation expense	872	1,464
Asset impairment, store closure and disposal of property and equipment	7,689	433
Other operating activities	488	18
Changes in operating assets and liabilities:
Accounts receivable, net	937	192
Inventories	650	125
Prepaid expenses and other assets	(3,000)	3,322
Accounts payable	3,309	303
Operating lease liabilities	(4,060)	(15,281)
Accrued expenses and other liabilities	(895)	(2,202)
Net cash (used in) provided by operating activities:	(4,923)	6,988
Cash flows from investing activities:
Purchases of property and equipment	(7,333)	(5,230)
Net cash used in investing activities:	(7,333)	(5,230)
Cash flows from financing activities:
Borrowings under credit facility	39,786
Repayments under credit facility	(16,700)
Payment of debt issuance costs	(438)
Proceeds from exercise of stock options		173
Employee taxes on certain stock-based payment arrangements	(77)	(35)
Treasury stock repurchases		(3,467)
Distributions to non-controlling interest	(172)	(177)
Contributions from non-controlling interest	143	39
Net cash provided by (used in) financing activities:	22,542	(3,467)
Net increase (decrease) in cash and cash equivalents	10,286	(1,709)
Cash and cash equivalents at beginning of period	18,806	19,775
Cash and cash equivalents at end of period	29,092	18,066
Supplemental cash flow information:
Income taxes paid	18	180
Interest paid	330	48
Supplemental non-cash investing and financing activities:
Unpaid liability for purchases of property and equipment	$ 183	$ 583

Organization and Other Matters

Organization and Other Matters	6 Months Ended
	Jun. 28, 2020
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, owns and operates more than 400 company-owned shops in the United States. Additionally, Potbelly franchisees operate over 40 shops in the United States. Basis of Presentation The unaudited condensed consolidated financial statements and notes herein should be read in conjunction with the audited consolidated financial statements of Potbelly Corporation and its subsidiaries and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 29, 2019. The unaudited condensed consolidated financial statements included herein have been prepared by the Company without audit, pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) regarding interim financial reporting. Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) have been condensed or omitted pursuant to the SEC rules and regulations. In the opinion of management, all adjustments, which are of a normal and recurring nature (except as otherwise noted), that are necessary to present fairly the Company’s balance sheet as of June 28, 2020 and December 29, 2019, its statement of operations for the 13 and 26 weeks ended June 28, 2020 and June 30, 2019, the statement of equity for the 13 and 26 weeks ended June 28, 2020 and June 30, 2019, and its statement of cash flows for the 26 weeks ended June 28, 2020 and June 30, 2019 have been included. The consolidated statements of operations for the interim periods presented herein are not necessarily indicative of the results to be expected for the full year. The Company does not have any components of other comprehensive income recorded within its consolidated financial statements and therefore, does not separately present a statement of comprehensive income in its condensed consolidated financial statements. COVID-19 On January 30, 2020, the World Health Organization (“WHO”) announced a global health emergency because of a new strain of coronavirus ("COVID-19") and the risks to the international community as the virus spreads globally. On March 11, 2020, the WHO classified the COVID-19 outbreak as a pandemic, based on the rapid increase in exposure globally. In response to the pandemic, many states and jurisdictions in which we operate have issued stay-at-home orders and other measures aimed at slowing the spread of the coronavirus. We initially closed the vast majority our dining rooms and shifted to off-premise operations only, and we experienced a sudden and drastic decrease in revenues. We continue to follow guidance from local authorities in determining the appropriate restrictions to put in place for each shop. The majority of our shops have reopened their dining rooms with restrictions, such as social distancing and limited capacities, to ensure the health and safety of our guests and employees. The disruption in operations and reduction in revenues have led the Company to consider the impact of the COVID-19 pandemic on the recoverability of its assets, including property and equipment, right-of-use assets for operating leases, goodwill and intangible assets, and others. Due to the impact of the COVID-19 pandemic, the Company evaluated its goodwill, intangible assets, and long-lived assets, which includes property and equipment and right-of-use assets for operating leases for impairment. T he Company did not record any impairment to its goodwill or indefinite-lived intangible assets during the 13 and 26 weeks ended June 28, 2020. T he ultimate severity and longevity of the COVID-19 pandemic is unknown, and therefore, it is possible that impairments could be identified in future periods, and such amounts could be material. See Note 3 for further details. The Company recognized an income tax benefit of $3.7 million during the first quarter of 2020 primarily due to the impact of the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”). The Company estimates that it will be able to obtain a tax refund of $3.7 million from the carryback of NOLs and a refund of prior AMT credits. The Company received $1.1 million of this refund in July 2020 and expects to receive the remaining $2.6 million before the end of the current year. See Note 5 for further details. To preserve financial flexibility, the Company drew the $40.0 million of available capacity under its revolving credit facility on March 17, 2020. The Company subsequently repaid $16.7 million of these borrowings during the 13 weeks ended June 28, 2020. See Note 7 for further details. The full impact of the COVID-19 outbreak continues to evolve as of the date of this report. Due to the rapid development and fluidity of this situation, the Company cannot determine the ultimate impact that the COV ID-19 pandemic will have on its c onsolidated financial condition, liquidity, and future results of operations, and therefore any prediction as to the ultimate impact on the Company’s consolidated financial condition, liquidity, and future results of operations is uncertain. Resolution of Substantial Doubt Related to Going Concern Assessment Under ASC 205, Presentation of Financial Statements Principles of Consolidation The unaudited condensed 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”); seven of LLC’s wholly owned subsidiaries and LLC’s seven joint ventures, collectively, the “Company.” All 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 seven joint venture investments. The Company has ownership interests ranging from 51-80% in these consolidated joint ventures. Fiscal Year The Company uses a 52/53-week fiscal year that ends on the last Sunday of the calendar period. Approximately every five or six years a 53rd week is added. Fiscal year 2020 and 2019 both consist of 52 weeks. The fiscal quarters ended June 28, 2020 and June 30, 2019 each consisted of 13 weeks. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Significant estimates include amounts for long-lived assets and income taxes. Actual results could differ from those estimates. Recent Accounting Pronouncements On December 30, 2019, the Company adopted Accounting Standard Update No. 2016-13, Financial Instruments—Credit Losses (Topic 326)

Revenue

Revenue	6 Months Ended
	Jun. 28, 2020
Revenue From Contract With Customer [Abstract]
Revenue	(2) Revenue The Company primarily earns revenue at a point in time for sandwich shop sales which can occur in person at the shop, over our online or app platforms, or through a third-party platform. Revenue is recorded net of sales-related taxes collected from customers. The payment on these sales is due at the time of the customer’s purchase. The Company also receives royalties from franchisees on their respective sales, which are recognized at the point in time the sale is made and invoiced weekly. Potbelly also records revenue from sales over time related to upfront franchise fees, gift card redemptions and breakage. For the 13 and 26 weeks ended June 28, 2020, revenue recognized from all revenue sources on point in time sales was $56.0 million and $143.5 million, respectively, and revenue recognized from sales over time was $0.2 million and $0.3 million, respectively. For the 13 and 26 weeks ended June 30, 2019, revenue recognized from all revenue sources on point in time sales was $105.5 million and $203.3 million, respectively, and revenue recognized from sales over time was $0.1 million and $0.4 million, respectively. Franchise Revenue Potbelly licenses intellectual property and trademarks to franchisees through franchise agreements. As part of these franchise agreements, Potbelly receives an upfront payment from the franchisee, which the Company recognizes over the term of the franchise agreement. The Company records a contract liability for the unearned portion of the upfront franchise payments. Gift Card Redemptions / Breakage Revenue Potbelly sells gift cards to customers, records the sale as a contract liability and recognizes the associated revenue as the gift card is redeemed. A portion of these gift cards are not redeemed by the customer, which is recognized by the Company as revenue as a percentage of customers gift card redemptions. The expected breakage amount recognized is determined by a historical data analysis on gift card redemption patterns. Loyalty Program During the second quarter of 2020, the Company implemented a new customer loyalty program for customers using the Potbelly Perks application at the point of sale. The customer will typically earn 10 points for every dollar spent, and the customer will earn a free entrée after earning 1,000 points. The Company defers revenue associated with the estimated selling price of points earned by Potbelly Perks members towards free entrees as each point is earned, and a corresponding liability is established in deferred revenue. The deferral is based on the estimated value of the product for which the reward is expected to be redeemed, net of estimated unredeemed points. Once a customer earns a free entrée, that entree reward will expire after 30 days. Any point in a customer’s account that does not go toward earning a full entrée will expire a year after the point is earned. When points are redeemed, the Company recognizes revenue for the redeemed product and reduces deferred revenue. Contract Liabilities As described above, the Company records current and noncurrent contract liabilities for upfront franchise fees, gift cards and the loyalty program. There are no other contract liabilities or contract assets recorded by the Company. The opening and closing balances of the Company’s current and noncurrent contract liabilities from contracts with customers were as follows: Current Contract Liability Noncurrent Contract Liability (Thousands) (Thousands) Beginning balance as of December 30, 2019 $ (1,594 ) $ (2,054 ) Ending balance as of June 28, 2020 (1,626 ) (1,831 ) Increase (decrease) in contract liability $ 32 $ (223 ) The aggregate value of remaining performance obligations on outstanding contracts was $3.5 million as of June 28, 2020. The Company expects to recognize revenue related to contract liabilities as follows (in thousands), which may vary based upon franchise activity as well as gift card redemption patterns: Years Ending Amount 2020 $ 1,039 2021 478 2022 244 2023 195 2024 162 Thereafter 1,339 Total revenue recognized $ 3,457 For the 13 and 26 week s ended June 28, 2020, the amount of revenue recognized related to the December 30, 2019 liability ending balance was $0.4 million and $0.9 million, respectively. For the 13 and 26 weeks ended June 30, 2019, the amount of revenue recognized related to the December 30, 2018 liability ending balance was $0.6 million and $1.5 million, respectively. This revenue related to the recognition of gift card redemptions and upfront franchise fees. For the 13 and 26 weeks ended June 28, 2020 and June 30, 2019, the Company did not recognize any revenue from obligations satisfied (or partially satisfied) in prior periods.

Fair Value Measurement

Fair Value Measurement	6 Months Ended
	Jun. 28, 2020
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 and lease right-of-use assets, on a quarterly basis or whenever events or circumstances indicate that the carrying amount of an asset may not be recoverable. Shop-level assets and right-of-use assets are grouped at the individual shop-level for the purpose of the impairment assessment. Recoverability of an asset group is measured by a comparison of the carrying amount of an asset group to its estimated undiscounted future cash flows expected to be generated by the asset group. 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 group exceeds the fair value of the asset group. 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. The fair value of right-of-use assets is estimated using market comparative information for similar properties. 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 the 13 and 26 weeks ended June 28, 2020, 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 an impairment charge of $0.9 million and $6.8 million for the 13 and 26 weeks ended June 28, 2020, respectively, primarily driven by the expected impact of the COVID-19 pandemic on future cash flows. T he ultimate severity and longevity of the COVID-19 pandemic is unknown, and therefore, it is possible that impairments could be identified in future periods, and such amounts could be material. Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Assets recognized or disclosed at fair value on the consolidated financial statements on a nonrecurring basis include items such as leasehold improvements, property and equipment, operating lease assets, goodwill, and other intangible assets. These assets are measured at fair value if determined to be impaired. 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. Due to the initial impact of the COVID-19 pandemic to the global economy, including but not limited to, the volatility of the Company's stock price as well as that of its competitors, declining sales at the Company's restaurants and the challenging environment for the restaurant industry generally, the Company determined that there were indicators of potential impairment of its goodwill and indefinite-lived intangible assets during the first quarter of 2020. As such, the Company performed an impairment assessment for both goodwill and indefinite lived intangible assets and concluded that the fair value of these assets exceeded their carrying values. The Company has not recorded any impairment to its goodwill or indefinite-lived intangible assets during the 13 and 26 weeks ended June 28, 2020. T he ultimate severity and longevity of the COVID-19 pandemic is unknown, and therefore, it is possible that impairments could be identified in future periods, and such amounts could be material.

Loss Per Share

Loss Per Share	6 Months Ended
	Jun. 28, 2020
Earnings Per Share [Abstract]
Loss Per Share	(4) Loss 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. In periods of a net loss, no potential common shares are included in diluted shares outstanding as the effect is anti-dilutive. For the 13 and 26 weeks ended June 28, 2020, and June 30, 2019, the Company had a loss per share, and therefore potentially dilutive shares were excluded from the calculation. The following table summarizes the loss per share calculation: For the 13 Weeks Ended For the 26 Weeks Ended June 28, June 30, June 28, June 30, 2020 2019 2020 2019 Net loss attributable to Potbelly Corporation $ (22,216 ) $ (1,866 ) $ (35,552 ) $ (20,305 ) Weighted average common shares outstanding-basic 23,773 23,908 23,709 24,021 Plus: Effect of potential stock options exercise — — — — Weighted average common shares outstanding-diluted 23,773 23,908 23,709 24,021 Loss per share available to common stockholders-basic $ (0.93 ) $ (0.08 ) $ (1.50 ) $ (0.85 ) Loss per share available to common stockholders-diluted $ (0.93 ) $ (0.08 ) $ (1.50 ) $ (0.85 ) Potentially dilutive shares that are considered anti-dilutive: Common share options 2,998 2,377 2,646 2,382

Income Taxes

Income Taxes	6 Months Ended
	Jun. 28, 2020
Income Tax Disclosure [Abstract]
Income Taxes	(5) Income Taxes On March 27, 2020, the CARES Act was enacted into law. The CARES Act is a tax and spending package intended to provide economic relief to address the impact of the COVID-19 pandemic. The CARES Act includes several significant business tax provisions that, among other things, would eliminate the taxable income limit for certain net operating losses (“NOLs”) and allow businesses to carry back NOLs arising in 2018, 2019, and 2020 to the five prior tax years, accelerate refunds of previously generated corporate alternative minimum tax (“AMT”) credits, loosen the business interest limitation under section 163(j), and fix the qualified improvement property regulations in the 2017 Tax Cuts and Jobs Act. As a result of the CARES Act, the Company estimates that it will be able to obtain a tax refund of $3.7 million from the carryback of NOLs and a refund of prior AMT credits. The $3.7 million tax receivable is recorded in other current assets on the Company’s condensed consolidated balance sheet as of June 28, 2020. The Company received $1.1 million of this refund in July 2020 and expects to receive the remaining $2.6 million before the end of the current year. The interim tax provision is determined using an estimated annual effective tax rate and is adjusted for discrete taxable events that occur during the quarter. The Company recognized an income tax benefit of $3.7 million during the first quarter of 2020 primarily due to the impact of the Cares Act discussed above. The Company recorded a tax expense of $13.6 million during the first quarter of 2019 due to the Company recording a non-cash charge to income tax expense for the recognition of a full valuation allowance against its net deferred tax assets. The Company continues to record a valuation allowance against all of its deferred tax assets as June 28, 2020. The Company did not provide for an income tax benefit on its pre-tax loss for the 13 and 26 weeks ended June 28, 2020 and June 30, 2019. The Company regularly assesses the need for a valuation allowance related to its deferred tax assets, which includes consideration of both positive and negative evidence related to the likelihood of realization of such deferred tax assets to determine, based on the weight of the available evidence, whether it is more-likely-than-not that some or all of its deferred tax assets will not be realized. In its assessment, the Company considers recent financial operating results, projected future taxable income, the reversal of existing taxable differences, and tax planning strategies. The Company recorded a full valuation allowance against its net deferred tax assets during the first quarter of 2019 resulting in a non-cash charge to income tax expense of $13.6 million. The Company continued to maintain a valuation allowance against all of its deferred tax assets as of June 28, 2020. The Company assesses the likelihood of the realization of its deferred tax assets each quarter and the valuation allowance is adjusted accordingly.

Leases

Leases	6 Months Ended
	Jun. 28, 2020
Leases [Abstract]
Leases	(6) Leases We determine if a contract contains a lease at inception. The Company leases retail shops, warehouse and office space under operating leases. 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. Operating lease assets and liabilities are recognized at the lease commencement date. Operating lease liabilities represent the present value of lease payments not yet paid. Operating lease assets represent our right to use an underlying asset and are based upon the operating lease liabilities adjusted for prepayments or accrued lease payments, initial direct costs, lease incentives, and impairment of operating lease assets. To determine the present value of lease payments not yet paid, we estimate incremental secured borrowing rates corresponding to the maturities of the leases. The Company estimates this rate based on prevailing financial market conditions, comparable company and credit analysis, and management judgment. We recognize expense for these leases on a straight-line basis over the lease term. Additionally, tenant incentives used to fund leasehold improvements are recognized when earned and reduce our right-of-use asset related to the lease. These are amortized through the right-of-use asset as reductions of expense over the lease term. As a result of COVID-19, the Company suspended the payment of rent on the majority of its leases and has been in discussions with landlords regarding the restructuring of those leases in light of various contractual and legal defenses. The Company entered into 107 amendments with our respective landlords during the thirteen weeks ended June 28, 2020. Under these agreements, certain rent payments will be abated, deferred or modified without penalty for various periods, generally covering two to four months of rent payments. In April 2020, the Financial Accounting Standards Board issued guidance allowing entities to make a policy election whether to account for lease concessions related to the COVID-19 pandemic as lease modifications. The election applies to any lessor-provided lease concession related to the impact of the COVID-19 pandemic, provided the concession does not result in a substantial increase in the rights of the lessor or in the obligations of the lessee. During the thirteen weeks ended June 28, 2020, we received concessions from certain landlords in the form of rent deferrals and abatements which were not substantial, and we have elected to not account for these rent concessions as lease modifications. During the thirteen weeks ended June 28, 2020, the Company terminated the leases for six company-owned shops which will be permanently closed. The Company incurred $0.3 million in lease termination fees related to these leases. Upon termination of these leases, the Company derecognized ROU assets of $3.6 million and lease liabilities of $3.8 million that resulted in a net gain of $0.2 million that is recorded in general and administrative expenses. Operating lease term and discount rate were as follows: June 28, June 30, 2020 2019 Weighted average remaining lease term (years) 8.16 8.72 Weighted average discount rate 7.90 % 8.03 % Certain of the Company’s operating lease agreements include variable payments that are passed through by the landlord, such as common area maintenance and real estate taxes, as well as variable payments based on percentage rent for certain of our shops. Pass-through charges and payments based on percentage rent are included within variable lease cost. The components of lease cost were as follows: 13 weeks ending 26 weeks ending June 28, June 30, June 28, June 30, Classification 2020 2019 2020 2019 Operating lease cost Occupancy and General and administrative expenses 11,817 11,611 23,587 22,606 Variable lease cost Occupancy 2,918 3,649 6,240 7,153 Total lease cost $ 14,735 $ 15,260 $ 29,827 $ 29,759 Supplemental disclosures of cash flow information related to leases were as follows: 13 weeks ending 26 weeks ending June 28, June 30, June 28, June 30, 2020 2019 2020 2019 Operating cash flows rent paid for operating lease liabilities 1,528 11,788 13,507 23,726 Operating right-of-use assets obtained in exchange for new operating lease liabilities 8,002 2,735 13,536 3,657 Reduction in operating right-of-use assets due to lease terminations (3,442 ) (1,320 ) (4,881 ) (5,847 ) As of June 28, 2020, the Company had no real estate leases entered into that had not yet commenced. Maturities of lease liabilities were as follows as of June 28, 2020: Operating Leases Remainder of 2020 31,433 2021 46,600 2022 40,477 2023 35,598 2024 32,805 2025 30,552 Thereafter 112,663 Total lease payments 330,128 Less: imputed interest (89,721 ) Present value of lease liabilities $ 240,407

Debt and Credit Facilities

Debt and Credit Facilities	6 Months Ended
	Jun. 28, 2020
Debt Disclosure [Abstract]
Debt and Credit Facilities	(7) Debt and Credit Facilities On August 7, 2019, the Company entered into a second amended and restated revolving credit facility agreement (the "Credit Agreement") with JPMorgan Chase Bank, N.A. (“JPMorgan”) that expires in July 2022 On March 17, 2020, the Company fully drew the available capacity of $39.8 million under the Credit Agreement as a precautionary measure in order to increase its cash position and preserve financial flexibility in light of current uncertainty in the global markets resulting from the COVID-19 pandemic. In accordance with the terms of the Credit Agreement, the proceeds from these borrowings may in the future be used for working capital, general corporate or other permitted purposes. The Credit Agreement was subsequently amended as of May 15, 2020 (the “Credit Agreement Amendment”) to, among other things (i) change the maturity date from July 31, 2022 to March 31, 2022; (ii) eliminate the $20.0 million expansion feature; (iii) amend the interest rate to the Company’s option at either (a) a eurocurrency rate determined by reference to the applicable LIBOR rate with a 1.00% floor plus a margin of 5.00% or (b) a prime rate as announced by JP Morgan plus 4.00%; (iv) amend the commitment fee to 1.00% per annum in respect of any unused commitments under the credit facility; (v) implement additional restrictions on restricted payments, acquisitions and other indebtedness; and (vi) implement additional financial covenants. Per the terms of the Credit Agreement Amendment, the Company repaid $15.0 million of its outstanding borrowing at the signing of the Credit Agreement Amendment, and may re-borrow this $15.0 million when its cash balance held by JP Morgan declines below $28.0 million. Lastly, the Company was required to pay a fee of 1% of the outstanding loan balance after the signing of the Credit Agreement Amendment. On July 17, 2020, the Company entered into Amendment No. 2 (the “Second Amendment”) to the Credit Agreement to, among other things: (i) revise its financial covenants; (ii) decrease the aggregate amount of loan commitment available under the Credit Agreement from $40.0 million to $30.0 million after March 31, 2021 and (iii) decrease the interest rate to the Company’s option at either (a) a eurocurrency rate determined by reference to the applicable LIBOR rate with a 1.00% floor plus a margin of 4.75% or (b) a prime rate as announced by JP Morgan plus 2.25%. Per the terms of the Second Amendment, the Company repaid $14.5 million of its outstanding borrowing at the signing of the Second Amendment, and may reborrow the entire amount available under the credit facility when its cash balance held by JP Morgan declines below $10.0 million in total. As of June 28, 2020, the Company had $23.1 million outstanding under the Credit Agreement. There were no borrowings outstanding as of June 30, 2019. The Second Amendment includes financial covenants that require the Company to (i) maintain periodic minimum liquidity levels through February 28, 2022 ranging from $15.0 million to $30.0 million and (ii) maintain monthly minimum adjusted EBITDA thresholds for specified computation periods through February 28, 2022 ranging from ($18.0) million to $8.3 million. The Company is currently in compliance with all debt covenants as of June 28, 2020. On April 10, 2020, Potbelly Sandwich Works, LLC, an indirect subsidiary of the Company, was granted a loan (the “Loan”) from JPMorgan Chase Bank, N.A. in the aggregate amount of $10.0 million, pursuant to the Paycheck Protection Program under Division A, Title I of the CARES Act, which was enacted March 27, 2020. On April 28, 2020, the Company repaid the $10.0 million proceeds from the loan.

Capital Stock

Capital Stock	6 Months Ended
	Jun. 28, 2020
Equity [Abstract]
Capital Stock	(8) Capital Stock On May 8, 2018, the Company announced that its Board of Directors authorized a stock repurchase program for up to $65.0 million of its outstanding common stock. The 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 and Exchange Act of 1934, as amended) or in privately negotiated transactions. The number of common shares actually repurchased, and the timing and price of repurchases, will depend upon market conditions, SEC requirements and other factors. Purchases may be started or stopped at any time without prior notice depending on market conditions and other factors. For the 13 and 26 weeks ended June 28, 2020, the Company did not repurchase any shares of its common stock. In light of the COVID-19 pandemic, the Company does not have plans to repurchase any common stock under its stock repurchase program at this time. For the 13 and 26 weeks ended June 30, 2019, the Company repurchased 350,659 shares and 485,659 shares of its common stock for approximately $2.3 million and $3.5 million, respectively, under the stock repurchase program, including cost and commission, in open market transactions. Repurchased shares are included as treasury stock in the condensed consolidated balance sheets and the condensed consolidated statements of equity.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 28, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	(9) Stock-Based Compensation Stock options The Company has awarded stock options to certain employees of the Company and certain non-employee members of its Board of Directors. The grants generally vest over a four-year A summary of stock option activity for the 26 weeks ended June 28, 2020 is as follows: Options Shares (Thousands) Weighted Average Exercise Price Aggregate Intrinsic Value (Thousands) Weighted Average Remaining Term (Years) Outstanding—December 29, 2019 1,774 $ 11.34 $ — 4.33 Granted — — Exercised — — Canceled (33 ) 10.51 Outstanding—June 28, 2020 1,741 11.35 $ — 3.76 Exercisable—June 28, 2020 1,576 $ 11.14 $ — 3.38 Stock-based compensation related to stock options is measured at the grant date based on the calculated fair value of the award, and is recognized as expense over the requisite employee service period, which is generally the vesting period of the grant with a corresponding increase to additional paid-in capital. For the 13 and 26 weeks ended June 28, 2020, the Company recognized stock-based compensation expense related to stock options of $0.1 million and $0.3 million, respectively. For the 13 and 26 weeks ended June 30, 2019, the Company recognized stock-based compensation expense related to stock options of $0.3 million and $0.6 million, respectively. As of June 28, 2020, unrecognized stock-based compensation expense for stock options was $0.5 million, which will be recognized through fiscal year 2022. The Company records stock-based compensation expense within general and administrative expenses in the condensed consolidated statements of operations. Restricted stock units The Company awards restricted stock units (“RSUs”) to certain employees of the Company and certain non-employee members of its Board of Directors. The Board of Director grants have a vesting schedule of 50% on the first anniversary of the grant date and 50% on the second anniversary of the grant date. The employee grants vest in one-third increments over a three-year A summary of RSU activity for the 26 weeks ended June 28, 2020 is as follows: RSUs Number of RSUs (Thousands) Weighted Average Fair Value per Share Non-vested as of December 29, 2019 463 $ 7.59 Granted 963 2.48 Vested (168 ) 2.68 Canceled (1 ) 2.98 Non-vested as of June 28, 2020 1,257 $ 3.55 Performance stock units The Company awards performance share units (“PSUs”) to eligible employees. In June 2020 the Company issued 774,761 PSUs with a grant date fair value of $1.50 that was established using a Monte Carlo simulation model. These PSUs are subject to service and market vesting conditions. The PSUs will vest over the performance period of May 15, 2020 through May 15, 2025. Participants are entitled to receive a specified number of shares of the Company’s common stock contingent on the achievement of a stock return on the Company's common stock. Compensation expense for these awards will be amortized over an average expected service period of 1.8 years. In March 2019 the Company issued 188,414 PSUs with a grant date fair value of $8.46 per share. The PSUs will vest based on the Company’s achievement of certain targets related to adjusted EBITDA and same store sales goals, subject to continued service through the performance period. The PSUs will vest fully on the third anniversary of the grant date. The quantity of shares that will vest ranges from 0% to 200% of the targeted number of shares. If the defined minimum targets are not met, then no shares will vest. For the 26 weeks ended June 28, 2020 and June 30, 2019, no expense was recognized related to PSUs.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 28, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	(10) Commitments and Contingencies 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. In October 2017, plaintiffs filed a purported collective and class action lawsuit (the “Complaint”) in the United States District Court for the Southern District of New York against the Company alleging violations of the Fair Labor Standards Act (FLSA) and New York Labor Law (NYLL). The plaintiffs allege that the Company violated the FLSA and NYLL by not paying overtime compensation to our assistant managers and violated NYLL by not paying spread-of-hours pay. The Complaint was brought as a nationwide “collective action” under the FLSA and as a “class action” under NYLL. Since the filing of the Complaint, the plaintiffs filed a proposed amended complaint removing the NYLL class claim, but adding a proposed Illinois state law class action. In May 2019, the parties participated in a mediation and resolved the claims, which received final court approval on February 4, 2020. All charges related to the claims are reflected in the statement of operations.

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 28, 2020
Related Party Transactions [Abstract]
Related Party Transactions	(11) Related Party Transactions On May 10, 2020, the Company entered into a Settlement Agreement (the “Settlement Agreement”) with Intrinsic Investment Holdings, LLC, the Vann A. Avedisian Trust U/A 8/29/85, Vann A. Avedisian, KGT Investments, LLC, The Khimji Foundation, Mahmood Khimji, Bryant L. Keil and Neil Luthra (the foregoing, collectively with each of their respective affiliates, the “Vann Group”). In connection with the Settlement Agreement with the Vann Group, the Company issued 130,000 shares of common stock (including 41,311 shares issued to the Vann A. Avedisian Trust U/A 8/29/85, 43,571 shares issued to KGT Investments, LLC and 45,118 shares issued to The Khimji Foundation) to reimburse the Vann Group for its documented out-of-pocket costs, fees and expenses incurred in connection with the Settlement Agreement. The Company recorded expense of $0.4 million within general and administrative expenses related to the issuance of these shares. Based on a report of Schedule 13D filed May 11, 2020 by the Vann Group, the Vann Group beneficially owns 8.7% of the common stock of the Company.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 28, 2020
Subsequent Events [Abstract]
Subsequent Events	(12) Subsequent Events Credit Facility A second amendment to the Credit Agreement was entered into as of July 17, 2020. See Note 7 for further details. Lease Terminations As disclosed in Note 6, the Company continues to have discussions with its landlords about deferral or abatement of rent, restructured lease terms, and early terminations. Since June 28, 2020, the Company has terminated the leases for 9 company-owned shops which have been permanently closed. The Company incurred $0.5 million in lease termination fees related to these leases.

Organization and Other Matters

Organization and Other Matters (Policies)	6 Months Ended
	Jun. 28, 2020
Accounting Policies [Abstract]
Business	Business Potbelly Corporation (the “Company” or “Potbelly”), through its wholly owned subsidiaries, owns and operates more than 400 company-owned shops in the United States. Additionally, Potbelly franchisees operate over 40 shops in the United States.
Basis of Presentation	Basis of Presentation The unaudited condensed consolidated financial statements and notes herein should be read in conjunction with the audited consolidated financial statements of Potbelly Corporation and its subsidiaries and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 29, 2019. The unaudited condensed consolidated financial statements included herein have been prepared by the Company without audit, pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) regarding interim financial reporting. Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) have been condensed or omitted pursuant to the SEC rules and regulations. In the opinion of management, all adjustments, which are of a normal and recurring nature (except as otherwise noted), that are necessary to present fairly the Company’s balance sheet as of June 28, 2020 and December 29, 2019, its statement of operations for the 13 and 26 weeks ended June 28, 2020 and June 30, 2019, the statement of equity for the 13 and 26 weeks ended June 28, 2020 and June 30, 2019, and its statement of cash flows for the 26 weeks ended June 28, 2020 and June 30, 2019 have been included. The consolidated statements of operations for the interim periods presented herein are not necessarily indicative of the results to be expected for the full year. The Company does not have any components of other comprehensive income recorded within its consolidated financial statements and therefore, does not separately present a statement of comprehensive income in its condensed consolidated financial statements.
COVID-19	COVID-19 On January 30, 2020, the World Health Organization (“WHO”) announced a global health emergency because of a new strain of coronavirus ("COVID-19") and the risks to the international community as the virus spreads globally. On March 11, 2020, the WHO classified the COVID-19 outbreak as a pandemic, based on the rapid increase in exposure globally. In response to the pandemic, many states and jurisdictions in which we operate have issued stay-at-home orders and other measures aimed at slowing the spread of the coronavirus. We initially closed the vast majority our dining rooms and shifted to off-premise operations only, and we experienced a sudden and drastic decrease in revenues. We continue to follow guidance from local authorities in determining the appropriate restrictions to put in place for each shop. The majority of our shops have reopened their dining rooms with restrictions, such as social distancing and limited capacities, to ensure the health and safety of our guests and employees. The disruption in operations and reduction in revenues have led the Company to consider the impact of the COVID-19 pandemic on the recoverability of its assets, including property and equipment, right-of-use assets for operating leases, goodwill and intangible assets, and others. Due to the impact of the COVID-19 pandemic, the Company evaluated its goodwill, intangible assets, and long-lived assets, which includes property and equipment and right-of-use assets for operating leases for impairment. T he Company did not record any impairment to its goodwill or indefinite-lived intangible assets during the 13 and 26 weeks ended June 28, 2020. T he ultimate severity and longevity of the COVID-19 pandemic is unknown, and therefore, it is possible that impairments could be identified in future periods, and such amounts could be material. See Note 3 for further details. The Company recognized an income tax benefit of $3.7 million during the first quarter of 2020 primarily due to the impact of the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”). The Company estimates that it will be able to obtain a tax refund of $3.7 million from the carryback of NOLs and a refund of prior AMT credits. The Company received $1.1 million of this refund in July 2020 and expects to receive the remaining $2.6 million before the end of the current year. See Note 5 for further details. To preserve financial flexibility, the Company drew the $40.0 million of available capacity under its revolving credit facility on March 17, 2020. The Company subsequently repaid $16.7 million of these borrowings during the 13 weeks ended June 28, 2020. See Note 7 for further details. The full impact of the COVID-19 outbreak continues to evolve as of the date of this report. Due to the rapid development and fluidity of this situation, the Company cannot determine the ultimate impact that the COV ID-19 pandemic will have on its c onsolidated financial condition, liquidity, and future results of operations, and therefore any prediction as to the ultimate impact on the Company’s consolidated financial condition, liquidity, and future results of operations is uncertain.
Resolution of Substantial Doubt Related to Going Concern Assessment	Resolution of Substantial Doubt Related to Going Concern Assessment Under ASC 205, Presentation of Financial Statements
Principles of Consolidation	Principles of Consolidation The unaudited condensed 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”); seven of LLC’s wholly owned subsidiaries and LLC’s seven joint ventures, collectively, the “Company.” All 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 seven joint venture investments. The Company has ownership interests ranging from 51-80% in these consolidated joint ventures.
Fiscal Year	Fiscal Year The Company uses a 52/53-week fiscal year that ends on the last Sunday of the calendar period. Approximately every five or six years a 53rd week is added. Fiscal year 2020 and 2019 both consist of 52 weeks. The fiscal quarters ended June 28, 2020 and June 30, 2019 each consisted of 13 weeks.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Significant estimates include amounts for long-lived assets and income taxes. Actual results could differ from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements On December 30, 2019, the Company adopted Accounting Standard Update No. 2016-13, Financial Instruments—Credit Losses (Topic 326)

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 28, 2020
Revenue From Contract With Customer [Abstract]
Summary of Current and Noncurrent Contract Liabilities from Contracts with Customers	The opening and closing balances of the Company’s current and noncurrent contract liabilities from contracts with customers were as follows: Current Contract Liability Noncurrent Contract Liability (Thousands) (Thousands) Beginning balance as of December 30, 2019 $ (1,594 ) $ (2,054 ) Ending balance as of June 28, 2020 (1,626 ) (1,831 ) Increase (decrease) in contract liability $ 32 $ (223 )
Summary of Expected Revenue Recognition Related to Contract Liabilities	The Company expects to recognize revenue related to contract liabilities as follows (in thousands), which may vary based upon franchise activity as well as gift card redemption patterns: Years Ending Amount 2020 $ 1,039 2021 478 2022 244 2023 195 2024 162 Thereafter 1,339 Total revenue recognized $ 3,457

Loss Per Share (Tables)

Loss Per Share (Tables)	6 Months Ended
	Jun. 28, 2020
Earnings Per Share [Abstract]
Summary of Loss Per Share Calculation	The following table summarizes the loss per share calculation: For the 13 Weeks Ended For the 26 Weeks Ended June 28, June 30, June 28, June 30, 2020 2019 2020 2019 Net loss attributable to Potbelly Corporation $ (22,216 ) $ (1,866 ) $ (35,552 ) $ (20,305 ) Weighted average common shares outstanding-basic 23,773 23,908 23,709 24,021 Plus: Effect of potential stock options exercise — — — — Weighted average common shares outstanding-diluted 23,773 23,908 23,709 24,021 Loss per share available to common stockholders-basic $ (0.93 ) $ (0.08 ) $ (1.50 ) $ (0.85 ) Loss per share available to common stockholders-diluted $ (0.93 ) $ (0.08 ) $ (1.50 ) $ (0.85 ) Potentially dilutive shares that are considered anti-dilutive: Common share options 2,998 2,377 2,646 2,382

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 28, 2020
Leases [Abstract]
Operating Lease Term and Discount Rate	Operating lease term and discount rate were as follows: June 28, June 30, 2020 2019 Weighted average remaining lease term (years) 8.16 8.72 Weighted average discount rate 7.90 % 8.03 %
Components of Lease Cost	The components of lease cost were as follows: 13 weeks ending 26 weeks ending June 28, June 30, June 28, June 30, Classification 2020 2019 2020 2019 Operating lease cost Occupancy and General and administrative expenses 11,817 11,611 23,587 22,606 Variable lease cost Occupancy 2,918 3,649 6,240 7,153 Total lease cost $ 14,735 $ 15,260 $ 29,827 $ 29,759
Supplemental Disclosures of Cash Flow Information Related to Leases	Supplemental disclosures of cash flow information related to leases were as follows: 13 weeks ending 26 weeks ending June 28, June 30, June 28, June 30, 2020 2019 2020 2019 Operating cash flows rent paid for operating lease liabilities 1,528 11,788 13,507 23,726 Operating right-of-use assets obtained in exchange for new operating lease liabilities 8,002 2,735 13,536 3,657 Reduction in operating right-of-use assets due to lease terminations (3,442 ) (1,320 ) (4,881 ) (5,847 )
Maturities of Lease Liabilities	Maturities of lease liabilities were as follows as of June 28, 2020: Operating Leases Remainder of 2020 31,433 2021 46,600 2022 40,477 2023 35,598 2024 32,805 2025 30,552 Thereafter 112,663 Total lease payments 330,128 Less: imputed interest (89,721 ) Present value of lease liabilities $ 240,407

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 28, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	A summary of stock option activity for the 26 weeks ended June 28, 2020 is as follows: Options Shares (Thousands) Weighted Average Exercise Price Aggregate Intrinsic Value (Thousands) Weighted Average Remaining Term (Years) Outstanding—December 29, 2019 1,774 $ 11.34 $ — 4.33 Granted — — Exercised — — Canceled (33 ) 10.51 Outstanding—June 28, 2020 1,741 11.35 $ — 3.76 Exercisable—June 28, 2020 1,576 $ 11.14 $ — 3.38
Summary of RSU Activity	A summary of RSU activity for the 26 weeks ended June 28, 2020 is as follows: RSUs Number of RSUs (Thousands) Weighted Average Fair Value per Share Non-vested as of December 29, 2019 463 $ 7.59 Granted 963 2.48 Vested (168 ) 2.68 Canceled (1 ) 2.98 Non-vested as of June 28, 2020 1,257 $ 3.55

Organization and Other Matter_2

Organization and Other Matters - Additional Information (Detail) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 28, 2020USD ($)ShopJointVenture	Mar. 29, 2020USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Jun. 28, 2020USD ($)ShopSubsidiaryJointVenture	Jun. 30, 2019USD ($)	Dec. 27, 2020USD ($)	Jul. 31, 2020USD ($)	Mar. 27, 2020USD ($)	Mar. 17, 2020USD ($)	Dec. 30, 2019USD ($)
Nature Of Business And Basis Of Presentation [Line Items]
Number of shops franchisees operate | Shop	40				40
Impairment charge	$ 900		$ 200		$ 6,800	$ 200
Income tax expense (benefit)	$ 41	$ (3,700)	$ 246	$ 13,600	(3,668)	$ 13,865
Tax refund from net operating loss carryback									$ 3,700
Repayments of borrowing					$ 16,700
Number of wholly owned subsidiaries | Subsidiary					7
Number of joint ventures | JointVenture	7				7
ASU 2016-13 (Topic 326) [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Reduction in accumulated deficit											$ 5
COVID 19 [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Impairment charge	$ 900				$ 6,800
Income tax expense (benefit)					3,700
Tax refund from net operating loss carryback	3,700				$ 3,700			$ 1,100
Repayments of borrowing	$ 16,700
COVID 19 [Member] | Revolving Credit Facility [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Line of credit facility amount borrowed										$ 40,000
COVID 19 [Member] | Scenario, Forecast [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Tax refund from net operating loss carryback							$ 2,600
Minimum [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Number of shops Potbelly Corporation owns or operates | Shop	400				400
Ownership interest rate					51.00%
Maximum [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Ownership interest rate					80.00%

Revenue - Additional Informatio

Revenue - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Amount of revenue recognized	$ 56,162,000	$ 105,630,000	$ 143,752,000	$ 203,717,000
Aggregate value of remaining performance obligation on outstanding contracts	3,457,000		3,457,000
Revenue recognized related to prior periods	0	0	0	0
January 1, 2018 Liability Ending Balance [Member]
Disaggregation Of Revenue [Line Items]
Amount of revenue recognized	400,000	600,000	900,000	1,500,000
Point in Time Sales [Member]
Disaggregation Of Revenue [Line Items]
Amount of revenue recognized	56,000,000	105,500,000	143,500,000	203,300,000
Over Time Sales [Member]
Disaggregation Of Revenue [Line Items]
Amount of revenue recognized	$ 200,000	$ 100,000	$ 300,000	$ 400,000

Revenue - Summary of Current an

Revenue - Summary of Current and Noncurrent Contract Liabilities from Contracts with Customers (Detail) $ in Thousands	6 Months Ended
	Jun. 28, 2020USD ($)
Revenue From Contract With Customer [Abstract]
Beginning balance of current contract liability	$ (1,594)
Ending balance of current contract liability	(1,626)
Increase (decrease) in contract liability	32
Beginning balance of noncurrent contract liability	(2,054)
Ending balance of noncurrent contract liability	(1,831)
Increase (decrease) in contract liability	$ (223)

Revenue - Summary of Expected R

Revenue - Summary of Expected Revenue Recognition Related to Contract Liabilities (Detail1) $ in Thousands	Jun. 28, 2020USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligations	$ 3,457
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligations	$ 1,039
Revenue, remaining performance obligation, expected timing of satisfaction, period	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligations	$ 478
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligations	$ 244
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligations	$ 195
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligations	$ 162
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2025-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligations	$ 1,339
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year

Revenue - Summary of Expected_2

Revenue - Summary of Expected Revenue Recognition Related to Contract Liabilities (Detail) $ in Thousands	Jun. 28, 2020USD ($)
Revenue From Contract With Customer [Abstract]
Revenue, remaining performance obligations	$ 3,457

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment charge	$ 0.9	$ 0.2	$ 6.8	$ 0.2
COVID 19 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment charge	$ 0.9		$ 6.8
Impact of the COVID 19 pandamic to thr global economy			Due to the initial impact of the COVID-19 pandemic to the global economy, including but not limited to, the volatility of the Company's stock price as well as that of its competitors, declining sales at the Company's restaurants and the challenging environment for the restaurant industry generally, the Company determined that there were indicators of potential impairment of its goodwill and indefinite-lived intangible assets during the first quarter of 2020. As such, the Company performed an impairment assessment for both goodwill and indefinite lived intangible assets and concluded that the fair value of these assets exceeded their carrying values. The Company has not recorded any impairment to its goodwill or indefinite-lived intangible assets during the 13 and 26 weeks ended June 28, 2020. The ultimate severity and longevity of the COVID-19 pandemic is unknown, and therefore, it is possible that impairments could be identified in future periods, and such amounts could be material.

Loss Per Share - Additional Inf

Loss Per Share - Additional Information (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Common Share Options [Member]
Loss Per Share [Line Items]
Potential common shares included in diluted shares outstanding	0	0	0	0

Loss Per Share - Summary of Los

Loss Per Share - Summary of Loss Per Share Calculation (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Loss Per Share [Line Items]
Net loss attributable to Potbelly Corporation	$ (22,216)	$ (1,866)	$ (35,552)	$ (20,305)
Weighted average common shares outstanding-basic	23,773	23,908	23,709	24,021
Weighted average common shares outstanding-diluted	23,773	23,908	23,709	24,021
Loss per share available to common stockholders-basic	$ (0.93)	$ (0.08)	$ (1.50)	$ (0.85)
Loss per share available to common stockholders-diluted	$ (0.93)	$ (0.08)	$ (1.50)	$ (0.85)
Common Share Options [Member]
Loss Per Share [Line Items]
Potentially dilutive shares that are considered anti-dilutive	2,998	2,377	2,646	2,382

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 28, 2020	Mar. 29, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 28, 2020	Jun. 30, 2019	Dec. 31, 2020	Jul. 31, 2020	Mar. 27, 2020
Tax refund from net operating loss carryback									$ 3,700
Income taxes receivable	$ 3,700				$ 3,700
Income tax expense (benefit)	$ 41	$ (3,700)	$ 246	$ 13,600	$ (3,668)	$ 13,865
Deferred tax assets, valuation allowance				$ 13,600
Scenario, Forecast [Member]
Income taxes receivable							$ 2,600
Subsequent Event [Member]
Income taxes receivable								$ 1,100

Leases - Additional Information

Leases - Additional Information (Detail) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 28, 2020USD ($)Shop	Jun. 28, 2020USD ($)Shop
Leases [Abstract]
Number of shop lease terminated | Shop	6	9
Lease termination fee	$ 0.3	$ 0.5
Derecognized right-of-use assets	3.6	3.6
Derecognized lease liabilities	3.8	3.8
Net gain on termination of lease	0.2
Additional operating leases payments related to shops not yet open, amount	$ 0	$ 0

Leases - Operating Lease Term a

Leases - Operating Lease Term and Discount Rate (Detail)	Jun. 28, 2020	Jun. 30, 2019
Leases [Abstract]
Weighted average remaining lease term (years)	8 years 1 month 28 days	8 years 8 months 19 days
Weighted average discount rate	7.90%	8.03%

Leases - Components of Lease Co

Leases - Components of Lease Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Lessee Lease Description [Line Items]
Total lease cost	$ 14,735	$ 15,260	$ 29,827	$ 29,759
Occupancy and General and Administrative Expenses [Member]
Lessee Lease Description [Line Items]
Operating lease cost	11,817	11,611	23,587	22,606
Occupancy Expenses [Member]
Lessee Lease Description [Line Items]
Variable lease cost	$ 2,918	$ 3,649	$ 6,240	$ 7,153

Leases - Supplemental Disclosur

Leases - Supplemental Disclosures of Cash Flow Information Related to Leases (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Leases [Abstract]
Operating cash flows rent paid for operating lease liabilities	$ 1,528	$ 11,788	$ 13,507	$ 23,726
Operating right-of-use assets obtained in exchange for new operating lease liabilities	8,002	2,735	13,536	3,657
Reduction in operating right-of-use assets due to lease terminations	$ (3,442)	$ (1,320)	$ (4,881)	$ (5,847)

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities (Detail) $ in Thousands	Jun. 28, 2020USD ($)
Operating Leases
Remainder of 2020	$ 31,433
2021	46,600
2022	40,477
2023	35,598
2024	32,805
2025	30,552
Thereafter	112,663
Total lease payments	330,128
Less: imputed interest	(89,721)
Present value of lease liabilities	$ 240,407

Debt and Credit Facilities - Ad

Debt and Credit Facilities - Additional Information (Detail) - USD ($)	Apr. 28, 2020	Aug. 07, 2019	Jul. 17, 2020	May 15, 2020	Jun. 28, 2020	Jun. 28, 2020	Apr. 10, 2020	Mar. 17, 2020	Jun. 30, 2019
Short Term Debt [Line Items]
Line of credit facility amount borrowed						$ 16,700,000
Credit Agreement Amendment [Member]
Short Term Debt [Line Items]
Upfront fee payable				1.00%
Second Credit Agreement Amendment [Member] | February 28, 2022 [Member] | Minimum [Member]
Short Term Debt [Line Items]
Minimum Liquidity Level						15,000,000
Minimum Building Adjusted EBITDA						(18,000,000)
Second Credit Agreement Amendment [Member] | February 28, 2022 [Member] | Maximum [Member]
Short Term Debt [Line Items]
Minimum Liquidity Level						30,000,000
Minimum Building Adjusted EBITDA						8,300,000
COVID 19 [Member]
Short Term Debt [Line Items]
Line of credit facility amount borrowed					$ 16,700,000
CARES Act Of 2020 [Member] | Potbelly Sandwich Works, LLC [Member] | JPMorgan Chase Bank, N.A. [Member] | Loan [Member]
Short Term Debt [Line Items]
Loan amount							$ 10,000,000
Repayments of proceeds from the loan	$ 10,000,000
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]
Short Term Debt [Line Items]
Credit facility agreement, interest rate		1.75%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] | Credit Agreement Amendment [Member]
Short Term Debt [Line Items]
Credit facility agreement, interest rate				5.00%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] | Second Credit Agreement Amendment [Member] | Subsequent Event [Member]
Short Term Debt [Line Items]
Credit facility agreement, interest rate			4.75%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Short Term Debt [Line Items]
Credit facility agreement, interest rate		1.25%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Credit Agreement Amendment [Member]
Short Term Debt [Line Items]
Credit facility agreement, interest rate				1.00%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Second Credit Agreement Amendment [Member] | Subsequent Event [Member]
Short Term Debt [Line Items]
Credit facility agreement, interest rate			1.00%
JPMorgan Chase Bank, N.A. [Member]
Short Term Debt [Line Items]
Commitment fee, percentage		0.20%
Credit facility agreement, amount outstanding					$ 23,100,000	$ 23,100,000			$ 0
JPMorgan Chase Bank, N.A. [Member] | Credit Agreement Amendment [Member]
Short Term Debt [Line Items]
Credit facility agreement, future increases				$ 20,000,000
Commitment fee, percentage				1.00%
Credit facility agreement, amount outstanding				$ 15,000,000
Line of credit facility amount borrowed				$ 28,000,000
JPMorgan Chase Bank, N.A. [Member] | Second Credit Agreement Amendment [Member] | Subsequent Event [Member]
Short Term Debt [Line Items]
Line of credit facility amount borrowed			$ 10,000,000
JPMorgan Chase Bank, N.A. [Member] | Maximum [Member] | Credit Agreement Amendment [Member]
Short Term Debt [Line Items]
Credit facility agreement, Maturity date				Mar. 31, 2022
JPMorgan Chase Bank, N.A. [Member] | Minimum [Member] | Credit Agreement Amendment [Member]
Short Term Debt [Line Items]
Credit facility agreement, Maturity date				Jul. 31, 2022
JPMorgan Chase Bank, N.A. [Member] | Prime Rate [Member] | Maximum [Member]
Short Term Debt [Line Items]
Credit facility agreement, interest rate		0.50%
JPMorgan Chase Bank, N.A. [Member] | Prime Rate [Member] | Minimum [Member]
Short Term Debt [Line Items]
Credit facility agreement, interest rate		0.00%
JPMorgan Chase Bank, N.A. [Member] | Prime Rate [Member] | Minimum [Member] | Credit Agreement Amendment [Member]
Short Term Debt [Line Items]
Credit facility agreement, interest rate				4.00%
JPMorgan Chase Bank, N.A. [Member] | Prime Rate [Member] | Minimum [Member] | Second Credit Agreement Amendment [Member] | Subsequent Event [Member]
Short Term Debt [Line Items]
Credit facility agreement, interest rate			2.25%
Revolving Credit Facility [Member] | Second Credit Agreement Amendment [Member] | Subsequent Event [Member]
Short Term Debt [Line Items]
Credit facility agreement, maximum principal amount			$ 40,000,000
Credit facility agreement, future increases			30,000,000
Revolving Credit Facility [Member] | COVID 19 [Member]
Short Term Debt [Line Items]
Line of credit facility amount borrowed								$ 40,000,000
Revolving Credit Facility [Member] | JPMorgan Chase Bank, N.A. [Member]
Short Term Debt [Line Items]
Credit facility agreement, expiration date		Jul. 31, 2022
Credit facility agreement, maximum principal amount		$ 40,000,000
Revolving Credit Facility [Member] | JPMorgan Chase Bank, N.A. [Member] | Credit Agreement Amendment [Member]
Short Term Debt [Line Items]
Line of credit facility amount borrowed				$ 15,000,000
Revolving Credit Facility [Member] | JPMorgan Chase Bank, N.A. [Member] | Second Credit Agreement Amendment [Member] | Subsequent Event [Member]
Short Term Debt [Line Items]
Line of credit facility amount borrowed			$ 14,500,000
Revolving Credit Facility [Member] | JPMorgan Chase Bank, N.A. [Member] | COVID 19 [Member]
Short Term Debt [Line Items]
Line of credit facility amount borrowed								$ 39,800,000
Revolving Credit Facility [Member] | JPMorgan Chase Bank, N.A. [Member] | Maximum [Member]
Short Term Debt [Line Items]
Credit facility agreement, future increases		$ 20,000,000

Capital Stock - Additional Info

Capital Stock - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019	May 08, 2018
Equity Class Of Treasury Stock [Line Items]
Stock repurchase program, authorized amount					$ 65,000,000
Common stock repurchased value		$ 2,323,000		$ 3,467,000
Stock Repurchase Program [Member]
Equity Class Of Treasury Stock [Line Items]
Common stock shares repurchased	0	350,659	0	485,659
Common stock repurchased value		$ 2,300,000		$ 3,500,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended		6 Months Ended
	Jun. 28, 2020	Mar. 31, 2019	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized stock-based compensation expense					$ 872,000	$ 1,464,000
Stock units issued					963,000
Stock units issued, grant-date fair value					$ 2.48
Stock-based compensation expense					$ 872,000	1,464,000
Average expected service period for amortization of compensation expense awards	1 year 9 months 18 days
Common Share Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized stock-based compensation expense			$ 100,000	$ 300,000	300,000	600,000
Unrecognized stock compensation expense	$ 500,000		500,000		$ 500,000
Unrecognized stock compensation expense, recognition period					2022
Stock-based compensation expense			$ 100,000	300,000	$ 300,000	600,000
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized stock-based compensation expense					0	0
Vesting description	The PSUs will vest over the performance period of May 15, 2020 through May 15, 2025.	The PSUs will vest fully on the third anniversary of the grant date. The quantity of shares that will vest ranges from 0% to 200% of the targeted number of shares. If the defined minimum targets are not met, then no shares will vest.
Stock units issued	774,761	188,414
Stock units issued, grant-date fair value	$ 1.50	$ 8.46
Stock-based compensation expense					$ 0	0
Performance Stock Units [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of targeted number of shares		0.00%
Performance Stock Units [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of targeted number of shares		200.00%
Employee and Non Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants vesting period					4 years
Method used to determine fair value of the options					Black-Scholes option pricing model
Stock options granted			0		0
Non-Employee Board Of Directors [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants vesting period					3 years
Recognized stock-based compensation expense			$ 300,000	700,000	$ 600,000	900,000
Unrecognized stock compensation expense	$ 3,200,000		3,200,000		$ 3,200,000
Unrecognized stock compensation expense, recognition period					2023
Vesting description					The employee grants vest in one-third increments over a three-year period.
Stock-based compensation expense			$ 300,000	$ 700,000	$ 600,000	$ 900,000
Non-Employee Board Of Directors [Member] | Restricted Stock Units (RSUs) [Member] | First Anniversary [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					50.00%
Non-Employee Board Of Directors [Member] | Restricted Stock Units (RSUs) [Member] | Second Anniversary [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					50.00%

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Detail) shares in Thousands	6 Months Ended	12 Months Ended
	Jun. 28, 2020$ / sharesshares	Dec. 29, 2019$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options outstanding shares, beginning balance | shares	1,774
Options, canceled | shares	(33)
Options outstanding shares, ending balance | shares	1,741	1,774
Options outstanding shares, exercisable | shares	1,576
Options outstanding weighted average exercise price, beginning balance | $ / shares	$ 11.34
Options, weighted average exercise price, canceled | $ / shares	10.51
Options outstanding weighted average exercise price, ending balance | $ / shares	11.35	$ 11.34
Options outstanding weighted average exercise price, exercisable | $ / shares	$ 11.14
Option outstanding weighted average remaining term	3 years 9 months 3 days	4 years 3 months 29 days
Options exercisable weighted average remaining term	3 years 4 months 17 days

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of RSU Activity (Detail) shares in Thousands	6 Months Ended
	Jun. 28, 2020$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of RSUs, Non-vested, beginning balance | shares	463
Number of RSUs, Granted | shares	963
Number of RSUs, Vested | shares	(168)
Number of RSUs, Canceled | shares	(1)
Number of RSUs, Non-vested, ending balance | shares	1,257
Weighted Average Fair Value per Share, Non-vested, beginning balance | $ / shares	$ 7.59
Weighted Average Fair Value per Share, Granted | $ / shares	2.48
Weighted Average Fair Value per Share, Vested | $ / shares	2.68
Weighted Average Fair Value per Share, Canceled | $ / shares	2.98
Weighted Average Fair Value per Share, Non-vested, ending balance | $ / shares	$ 3.55

Commitment and Contingencies -

Commitment and Contingencies - Additional Information (Detail)	1 Months Ended	6 Months Ended
	Oct. 31, 2017	Jun. 28, 2020
Commitments And Contingencies Disclosure [Abstract]
Purported collective and class action lawsuit filed date	October 2017
Settlement agreement date		February 4, 2020

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) shares in Thousands, $ in Millions	6 Months Ended
	Jun. 28, 2020	May 10, 2020
Related Party Transaction [Line Items]
Shares issued to related parties		130,000
Expense related to issuance of shares	$ 0.4
Vann A. Avedisian Trust [Member]
Related Party Transaction [Line Items]
Shares issued to related parties		41,311
Ownership percentage related party	8.70%
KGT Investments [Member]
Related Party Transaction [Line Items]
Shares issued to related parties		43,571
The Khimji Foundation [Member]
Related Party Transaction [Line Items]
Shares issued to related parties		45,118

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 28, 2020USD ($)Shop	Jun. 28, 2020USD ($)Shop
Subsequent Events [Abstract]
Number of shop lease terminated | Shop	6	9
Lease termination fee | $	$ 0.3	$ 0.5