Potbelly (PBPB) 10-Q/A 20 Nov 13 2013 Q3 Quarterly report (amended) Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 29, 2013	Nov. 08, 2013
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q/A	'
Amendment Flag	'false	'
Document Period End Date	29-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'PBPB	'
Entity Registrant Name	'Potbelly Corporation	'
Entity Central Index Key	'0001195734	'
Current Fiscal Year End Date	'--12-29	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	29,137,706

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 29, 2013	Dec. 30, 2012
In Thousands, unless otherwise specified
Current assets	'	'
Cash and cash equivalents	$25,119	$22,595
Accounts receivable, net of allowances of $12 and $16 as of September 29, 2013 and December 30, 2012, respectively	4,011	3,276
Inventories	2,125	1,910
Prepaid expenses and other current assets	5,667	4,683
Total current assets	36,922	32,464
Property and equipment, net	77,415	69,309
Intangible assets, net	3,404	3,404
Goodwill	1,428	1,428
Deferred income taxes	14,427	16,110
Deferred expenses, net and other assets	4,821	3,984
Total assets	138,417	126,699
Current liabilities	'	'
Accounts payable	3,154	2,586
Accrued expenses	17,758	14,553
Accrued dividend payable	49,854	'
Accrued income taxes	513	81
Current portion of long-term debt	14,074	74
Total current liabilities	85,353	17,294
Long-term debt, net of current portion	1,036	15,095
Deferred rent and landlord allowances	12,107	11,849
Other long-term liabilities	823	846
Total liabilities	99,319	45,084
Commitments and contingencies	'	'
Redeemable convertible preferred stock, $0.01 par value-authorized 17,183,632 shares; issued and outstanding 16,086,375 shares as of September 29, 2013, and December 30, 2012, respectively	265,440	250,343
Equity (deficit)	'	'
Common stock, $0.01 par value-authorized, 35,500,000 shares; issued and outstanding 4,351,869 and 4,233,977 shares as of September 29, 2013, and December 30, 2012, respectively	44	42
Warrants	942	1,552
Additional paid-in-capital	'	'
Accumulated deficit	-227,548	-170,518
Total stockholders' deficit	-226,562	-168,924
Non-controlling interest	220	196
Total deficit	-226,342	-168,728
Total liabilities and equity	$138,417	$126,699

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 29, 2013	Dec. 30, 2012
In Thousands, except Share data, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Allowances on accounts receivable	$12	$16
Redeemable convertible preferred stock, par value	$0.01	$0.01
Redeemable convertible preferred stock, authorized	17,183,632	17,183,632
Redeemable convertible preferred stock, issued	16,086,375	16,086,375
Redeemable convertible preferred stock, outstanding	16,086,375	16,086,375
Common stock, par value	$0.01	$0.01
Common stock, authorized	35,500,000	35,500,000
Common stock, issued	4,351,869	4,233,977
Common stock, outstanding	4,351,869	4,233,977

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 29, 2013	Sep. 23, 2012	Sep. 29, 2013	Sep. 23, 2012
Revenues	'	'	'	'
Sandwich shop sales, net	$77,747	$69,659	$224,214	$200,853
Franchise royalties and fees	274	210	737	553
Total revenues	78,021	69,869	224,951	201,406
Sandwich shop operating expenses	'	'	'	'
Cost of goods sold, excluding depreciation	23,014	20,238	65,767	58,389
Labor and related expenses	21,223	19,778	62,217	56,618
Occupancy expenses	9,295	8,135	26,826	22,885
Other operating expenses	7,946	7,317	23,058	20,767
General and administrative expenses	8,293	6,874	24,298	22,542
Depreciation expense	4,460	4,080	13,284	11,633
Pre-opening costs	364	630	1,083	1,760
Impairment and loss on disposal of property and equipment	250	'	329	78
Total expenses	74,845	67,052	216,862	194,672
Income from operations	3,176	2,817	8,089	6,734
Interest expense	97	176	330	427
Other expense	'	4	2	6
Income before income taxes	3,079	2,637	7,757	6,301
Income tax expense	905	84	2,792	765
Net income	2,174	2,553	4,965	5,536
Net income (loss) attributable to non-controlling interest	9	5	24	-35
Net income attributable to Potbelly Corporation	2,165	2,548	4,941	5,571
Dividend declared to common and preferred stockholders	-49,854	'	-49,854	'
Accretion of redeemable convertible preferred stock to maximum redemption value	-4,796	-5,545	-15,097	-13,887
Net loss attributable to common stockholders	($52,485)	($2,997)	($60,010)	($8,316)
Net loss per common share attributable to common stockholders:	'	'	'	'
Basic	($12.29)	($0.75)	($14.12)	($2.09)
Diluted	($12.29)	($0.75)	($14.12)	($2.09)
Weighted average shares outstanding:	'	'	'	'
Basic	4,268,953	3,972,873	4,250,819	3,972,873
Diluted	4,268,953	3,972,873	4,250,819	3,972,873

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Equity (Deficit) (USD $)

Total

Redeemable Convertible Preferred Stock [Member]

Redeemable Convertible Preferred Stock [Member]

Redeemable Convertible Preferred Stock [Member]

Redeemable Convertible Preferred Stock [Member]

Redeemable Convertible Preferred Stock [Member]

Redeemable Convertible Preferred Stock [Member]

Redeemable Convertible Preferred Stock [Member]

Equity (Deficit) [Member]

Equity (Deficit) [Member]

Equity (Deficit) [Member]

Equity (Deficit) [Member]

Equity (Deficit) [Member]

In Thousands, except Share data

Series A Preferred Stock [Member]

Series B Preferred Stock [Member]

Series C Preferred Stock [Member]

Series D Preferred Stock [Member]

Series E Preferred Stock [Member]

Series F Preferred Stock [Member]

Common Stock [Member]

Warrant [Member]

Additional Paid-in Capital [Member]

Accumulated Deficit [Member]

Noncontrolling Interest [Member]

Beginning Balance at Dec. 25, 2011

($185,302)

$239,848

$50,637

$45,062

$22,745

$17,570

$76,337

$27,497

$40

$2,068

'

($187,410)

'

Beginning Balance, Common Shares at Dec. 25, 2011

'

'

'

'

'

'

'

'

3,972,873

'

'

'

'

Beginning Balance, Preferred Shares at Dec. 25, 2011

'

16,086,375

3,697,377

3,290,294

1,646,595

1,250,000

4,194,366

2,007,743

'

'

'

'

'

Net income

5,536

'

'

'

'

'

'

'

'

'

'

5,571

-35

Contributions from non-controlling interest

230

'

'

'

'

'

'

'

'

'

'

'

230

Issuance of stock warrants

'

'

'

'

'

'

'

'

'

909

-909

'

'

Changes in redemption value of preferred stock

-13,887

13,887

3,210

2,856

1,441

1,113

3,524

1,743

'

'

-1,411

-12,476

'

Amortization of stock-based compensation

2,320

'

'

'

'

'

'

'

'

'

2,320

'

'

Ending Balance at Sep. 23, 2012

-191,103

253,735

53,847

47,918

24,186

18,683

79,861

29,240

40

2,977

'

-194,315

195

Ending Balance, Common Shares at Sep. 23, 2012

'

'

'

'

'

'

'

'

3,972,873

'

'

'

'

Ending Balance, Prefereed Shares at Sep. 23, 2012

'

16,086,375

3,697,377

3,290,294

1,646,595

1,250,000

4,194,366

2,007,743

'

'

'

'

'

Beginning Balance at Dec. 30, 2012

-168,728

250,343

52,796

46,983

23,715

18,319

79,861

28,669

42

1,552

'

-170,518

196

Beginning Balance, Common Shares at Dec. 30, 2012

4,233,977

'

'

'

'

'

'

'

4,233,977

'

'

'

'

Beginning Balance, Preferred Shares at Dec. 30, 2012

16,086,375

16,086,375

3,697,377

3,290,294

1,646,595

1,250,000

4,194,366

2,007,743

'

'

'

'

'

Net income

4,965

'

'

'

'

'

'

'

'

'

'

4,941

24

Beneficial Conversion Charge

'

'

'

'

'

'

'

'

'

'

50

-50

'

Contributions from non-controlling interest

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock warrants

2

'

'

'

'

'

'

'

2

'

'

'

'

Exercise of stock warrants, additional paid in capital

'

'

'

'

'

'

'

'

'

-610

610

'

'

Exercise of stock warrants, Shares

117,892

'

'

'

'

'

'

'

117,892

'

'

'

'

Dividend declared to common and preferred stockholders

-49,854

'

'

'

'

'

'

'

'

'

-49,854

'

'

Changes in redemption value of preferred stock

-15,097

15,097

3,582

3,188

1,609

1,251

3,523

1,944

'

'

46,824

-61,921

'

Amortization of stock-based compensation

2,370

'

'

'

'

'

'

'

'

'

2,370

'

'

Ending Balance at Sep. 29, 2013

($226,342)

$265,440

$56,378

$50,171

$25,324

$19,570

$83,384

$30,613

$44

$942

'

($227,548)

$220

Ending Balance, Common Shares at Sep. 29, 2013

4,351,869

'

'

'

'

'

'

'

4,351,869

'

'

'

'

Ending Balance, Prefereed Shares at Sep. 29, 2013

16,086,375

16,086,375

3,697,377

3,290,294

1,646,595

1,250,000

4,194,366

2,007,743

'

'

'

'

'

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 29, 2013	Sep. 23, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net income	$4,965	$5,536
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation	13,284	11,633
Deferred income tax	1,683	78
Deferred rent and landlord allowances	258	1,320
Amortization of stock compensation expense	2,370	2,320
Asset impairment and disposal of property and equipment	329	78
Amortization of debt issuance costs	46	154
Changes in operating assets and liabilities:	'	'
Accounts receivable, net	-735	-859
Inventories	-215	-93
Prepaid expenses and other assets	-1,475	1,506
Accounts payable	602	345
Accrued and other liabilities	3,267	-1,561
Net cash provided by operating activities	24,379	20,457
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Purchases of property and equipment	-21,265	-19,700
Net cash used in investing activities	-21,265	-19,700
CASH FLOWS FROM FINANCING ACTIVITIES	'	'
Proceeds from exercise of Series F warrants	2	'
Proceeds from long-term debt	'	14,000
Payments on debt	-59	-14,000
Payments on note payable	'	-55
Payment of deferred financing costs	'	-124
Payment of costs associated with initial public offering	-533	'
Contributions from non-controlling interest	'	230
Net cash (used in) provided by financing activities	-590	51
NET INCREASE IN CASH AND CASH EQUIVALENTS	2,524	808
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	22,595	24,146
CASH AND CASH EQUIVALENTS AT END OF PERIOD	25,119	24,954
Supplemental cash flow information:	'	'
Income taxes paid	727	794
Interest paid	261	621
Supplemental non-cash investing and financing activities:	'	'
Unpaid liability for purchases of property and equipment	2,561	1,636
Accretion of redeemable convertible preferred stock to maximum redemption value	15,097	13,887
Accrued dividend payable	$49,854	'

Organization_and_Other_Matters

Organization and Other Matters	9 Months Ended
	Sep. 29, 2013
Accounting Policies [Abstract]	'
Organization and Other Matters	'
	(1) Organization and Other Matters
	Business
	Potbelly Corporation (the “Company” or “Potbelly”), through its wholly owned subsidiary, Potbelly Sandwich Works LLC, operates Potbelly Sandwich Works sandwich shops in 18 states and the District of Columbia. As of December 30, 2012 and September 29, 2013, the Company had 264 and 288 company-operated shops, respectively. During fiscal year 2012, the Company opened 31 new shops and closed one shop. During the 39 weeks ended September 29, 2013, the Company opened 25 new shops and closed one shop.
	The Company also sells and administers franchises of new Potbelly Sandwich Works sandwich shops. The first domestic and international franchise locations administered by the Company opened during February 2011. As of the fiscal year ended 2012, five franchised shops were in operation domestically and ten franchised shops were in operation internationally. As of September 29, 2013, seven franchised shops were in operation in domestic locations and twelve franchised shops were in operation internationally.
	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 prospectus dated October 3, 2013, filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended (the “Securities Act”), with the Securities and Exchange Commission (“SEC”) on October 4, 2013. The unaudited condensed consolidated financial statements included herein have been prepared by the Company without audit, pursuant to the rules and regulations of the SEC regarding interim financial reporting. The December 30, 2012 condensed consolidated balance sheet was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (“GAAP”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the SEC’s rules and regulations, although management believes that the disclosures are adequate and make the information presented not misleading. 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 financial position as of December 30, 2012 and September 29, 2013, its statement of operations for the 13 weeks and 39 weeks ended September 23, 2012 and September 29, 2013 and its statement of cash flows for the 39 weeks ended September 23, 2012 and September 29, 2013 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 (loss) recorded within its consolidated financial statements, and, therefore, does not separately present a statement of comprehensive income (loss) in its consolidated financial statements.
	Initial Public Offering
	On October 9, 2013, the Company completed an initial public offering of 8,625,000 shares of common stock. Upon the completion of such initial public offering, all outstanding shares of preferred stock of the Company converted into common stock. See Note 8, “Subsequent Events.” Unless otherwise stated, the unaudited condensed consolidated financial statements and these notes thereto do not include the effects of the initial public offering as it was completed subsequent to September 29, 2013.
	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, Potbelly Sandwich Works, LLC (“LLC”) and 17 of LLC’s wholly owned subsidiaries, collectively, the “Company.” All significant intercompany balances and transactions have been eliminated in consolidation. For the Company’s consolidated joint venture, non-controlling interest represents the non-controlling partner’s share of the assets, liabilities and operations related to the joint venture investment in Potbelly Airport II Boston, LLC, related to one shop located in the Boston Logan International Airport. The Company owns a seventy-five percent interest in this consolidated joint venture.
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions, primarily related to long-lived assets, income taxes, stock-based compensation and common stock equity valuations, 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.
	Fiscal Year
	The Company uses a 52/53-week fiscal year that ends on the last Sunday of the calendar year. Approximately every six or seven years a 53rd week is added. Fiscal 2012 consisted of 53 weeks. The fiscal quarters ended September 23, 2012 and September 29, 2013 each consisted of 13 weeks and the fiscal year-to-date periods ended September 23, 2012 and September 29, 2013 each consisted of 39 weeks.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 29, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	(2) Fair Value Measurements
	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 investments. The carrying amounts of borrowings approximate fair value as interest rates on the credit facility varies with market interest rates and negotiated terms and conditions are consistent with market rates.
	The fair value of the Company, used to calculate the maximum redemption value of the redeemable convertible preferred stock and to measure the Black-Scholes value of the common stock as a key assumption in determining compensation expense associated with our stock options (see Note 7), was estimated using information derived from market data obtained during the initial public offering that was in process as of the fiscal quarter end and completed shortly thereafter.
	In addition, the Company assesses potential impairments to its long-lived assets, which includes property and equipment, whenever events or circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of an asset 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. 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. Shop-level assets are grouped together for the purpose of the impairment assessment. 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.

Earnings_per_share

Earnings per share	9 Months Ended
	Sep. 29, 2013
Earnings Per Share [Abstract]	'
Earnings per share	'
	(3) Earnings per share
	Basic and diluted income (loss) per common share attributable to common stockholders have been calculated using the weighted average number of common shares outstanding for the period. Diluted income (loss) per common share attributable to common stockholders is computed by dividing the income (loss) allocated to common stockholders utilizing the two-class method by the weighted average number of fully diluted common shares outstanding. Our redeemable convertible preferred stock are all considered participating securities requiring the two-class method to calculate basic and diluted earnings per share. In periods of a net loss attributable to common stockholders, the redeemable convertible preferred stock are excluded from the computation of basic earnings per share due to the fact that they are not required to fund losses and the redemption amount is not reduced as a result of losses. Dilutive securities do not include stock options awarded to employees that have a performance condition requiring the completion of an initial public offering of common stock (an “IPO”), as that performance condition was not satisfied at the reporting date and the holders of these options had no rights in our undistributed earnings at that time.
		13 Weeks Ended						39 Weeks Ended
		September 29,			September 23,			September 29,			September 23,
		2013			2012			2013			2012
	Calculation of undistributed (loss) for basic and diluted shares:
	Net income attributable to Potbelly Corporation	$	2,165		$	2,548		$	4,941		$	5,571
	Less: Dividend declared to common and preferred stockholders		(49,854	)		—			(49,854	)		—
	Less: Accretion of redeemable convertible preferred stock to maximum redemption value		(4,796	)		(5,545	)		(15,097	)		(13,887	)
	Undistributed loss for basic and diluted shares	$	(52,485	)	$	(2,997	)	$	(60,010	)	$	(8,316	)
	Allocation of undistributed(loss) to participating securities:
	Common shares	$	(52,485	)	$	(2,997	)	$	(60,010	)	$	(8,316	)
	Redeemable convertible preferred shares		—			—			—			—
	Undistributed (loss) income	$	(52,485	)	$	(2,997	)	$	(60,010	)	$	(8,316	)
	Weighted average common shares outstanding-basic		4,268,953			3,972,873			4,250,819			3,972,873
	Plus: Effect of potential stock options exercise		—			—			—			—
	Plus: Effect of potential warrant exercise		—			—			—			—
	Weighted average common shares outstanding-diluted		4,268,953			3,972,873			4,250,819			3,972,873
	Income (loss) per share available to common stockholders-basic	$	(12.29	)	$	(0.75	)	$	(14.12	)	$	(2.09	)
	Income (loss) per share available to common stockholders-diluted	$	(12.29	)	$	(0.75	)	$	(14.12	)	$	(2.09	)
	Potentially dilutive shares that are considered anti-dilutive:
	Common share options		4,744,664			4,446,049			4,744,664			4,446,049
	Warrants		241,704			378,996			241,704			378,996

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 29, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	(4) Income Taxes
	The Company recognized income tax expense of $2.8 million on pre-tax income of $7.8 million, or an effective tax rate of 36.0%, for the 39 weeks ended September 29, 2013, compared to income tax expense of $0.8 million on pre-tax income of $6.3 million, or an effective tax rate of 12.1%, for the 39 weeks ended September 23, 2012. The difference between the statutory rate and the effective tax rate is primarily attributable to state income taxes and certain federal and state tax credits. The increase in the effective tax rate primarily relates to the Company recognizing federal tax benefits, which were not recognized in the comparable prior period. The Company’s effective tax rate for the 39 weeks ended September 29, 2013 was primarily attributable to U.S. and state income taxes, offset by federal and local tax credits. The Company’s effective tax rate for the 39 weeks ended September 23, 2012 was primarily attributable to state income taxes. Based on management’s evaluation of certain factors, in the fourth quarter of fiscal 2012, the Company released a valuation allowance for all U.S. federal and state deferred tax assets.

Longterm_debt

Long-term debt	9 Months Ended
	Sep. 29, 2013
Debt Disclosure [Abstract]	'
Long-term debt	'
	(5) Long-term debt
	Long-term debt consisted of the following (in thousands):
		September 29,		December 30,
		2013		2012
	Senior credit facility (a)	$	14,000	$	14,000
	Note payable (b)		1,110		1,169
	Total long-term debt		15,110		15,169
	Less: Current portion		14,074		74
	Long-term debt, net of current portion	$	1,036	$	15,095
	The Company was in compliance with all of its debt covenants as of September 29, 2013 and December 30, 2012. On October 24, 2013, the Company used $14.0 million of the net proceeds from its initial public offering to repay the amounts outstanding under the credit facility. See Note 8, “Subsequent Events.”
	(a) Credit facility
	On September 21, 2012, the Company entered into a five-year revolving credit facility agreement with JPMorgan Chase Bank, N.A. that expires in September 2017 and provides for borrowings up to $35.0 million to fund capital expenditures for new shops, renovations and maintenance of existing shops, and to provide ongoing working capital for other general and corporate purposes. The credit facility contains customary representations, warranties and negative and affirmative covenants, including a requirement to maintain a maximum leverage ratio, as defined, of 2.25:1 and a minimum debt service coverage ratio, as defined, of 1.5:1. The credit facility also limits the restricted payments (primarily distributions and equity repurchases) that the Company may make, unless the Company obtains certain waivers or amendments from its lender. The Company was in compliance with these restrictions and conditions as of December 30, 2012 and September 29, 2013. The credit facility is secured by substantially all assets of the Company. Borrowings under the credit facility bear interest at interest rates based upon either the base rate or the London InterBank Offered Rate, plus or minus the applicable margins. The base rate is the higher of the prime rate and the federal funds rate, plus 0.50%. The Company’s outstanding borrowings under the credit facility had a weighted average interest rate of 1.35% as of December 30, 2012 and September 29, 2013. On October 24, 2013, the Company used $14.0 million of the net proceeds from its initial public offering to repay the amounts outstanding under the credit facility. See Note 8, “Subsequent Events.”
	(b) 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 interest rate of 6% and recorded interest expense of $57 thousand for the 39 weeks ended September 23, 2012 and $54 thousand for the 39 weeks ended September 29, 2013. Payment of interest and principal is made monthly. The final payment of the note will be made on April 1, 2015.

Capital_Stock_and_Warrants

Capital Stock and Warrants	9 Months Ended
	Sep. 29, 2013
Equity [Abstract]	'
Capital Stock and Warrants	'
	(6) Capital Stock and Warrants
	As of December 30, 2012 and September 29, 2013, the Company had authorized an aggregate of 52,683,632 shares of capital stock, of which 35,000,000 shares were designated as common stock, 500,000 shares were designated as non-voting common stock, and 17,183,632 shares were designated as preferred stock. The preferred stock consisted of 4,197,377 shares designated as Series A preferred stock, 3,375,221 shares designated as Series B preferred stock, 1,666,668 shares designated as Series C preferred stock, 1,250,000 shares designated as Series D preferred stock, 4,194,366 shares designated as Series E preferred stock, and 2,500,000 shares designated as Series F preferred stock. As of September 29, 2013, the Company had issued and outstanding 4,351,869 shares of common stock, no shares of non-voting common stock, 3,697,377 shares of Series A preferred stock, 3,290,294 shares of Series B preferred stock, 1,646,595 shares of Series C preferred stock, 1,250,000 shares of Series D preferred stock, 4,194,366 shares of Series E preferred stock, and 2,007,743 shares of Series F preferred stock.
	A roll-forward of the Company’s issued warrants as of September 29, 2013 is set forth below:
	Unexercised Warrants		Number of
			Warrants
	Outstanding—December 25, 2011			378,996
	Issuance of warrants at $8.16 per share (a)			241,704
	Exercise of warrants at $5.46 per share			(261,104	)
	Outstanding—December 30, 2012			359,596
	Exercise of warrants at $0.01 per share			(117,892	)
	Outstanding—September 29, 2013			241,704
	(a)	As part of the initial investment by outside investors in 2001, the Company issued stock warrants convertible to 200,000 shares of common stock at an exercise price of $5.00 per share, which expired on September 1, 2011. After the expiration of these warrants and to recognize past and continued service to the board of directors, the Company issued an additional 241,704 warrants at an exercise price of $8.16 per share. The Company used the following assumptions for purposes of valuing these warrants granted in 2011: common stock fair value of $8.16 per share; expected life of warrants-five years; volatility-53.0%; risk-free interest rate-1.1%; and dividend yield-0.0%.
	As of September 29, 2013, all series of preferred stock were subject to substantially the same general terms and conditions. Dividends accrued (whether or not declared) on each share of preferred stock at a rate of 6% per annum of the applicable liquidation value until the first to occur of (1) the date on which the applicable liquidation value of such share is paid to the holder in connection with a significant event, (2) the date on which such share is converted into common stock, or (3) the date on which such share is acquired by the Company. Dividends were cumulative, but were payable only upon their redemption or the occurrence of a significant event that would result in a distribution to their holders of less than 110% of the shares’ liquidation value (generally the applicable gross issuance price of the shares). A significant event includes a merger, sale of substantially all assets, change of control, or liquidation of the Company, but it does not include an IPO. The terms of the preferred stock provided that unpaid dividends would be forfeited upon any conversion of preferred stock into common stock.
	As of September 29, 2013, the terms of the preferred stock provided that all shares of preferred stock would automatically convert to common stock in the event of a qualified IPO, as defined; the election of the holders of a majority of the shares of preferred stock; or the conversion of at least a majority of the shares of issued preferred stock. None of the shares of preferred stock were mandatorily redeemable. Subsequent to December 24, 2014, preferred stock may have been redeemed upon a majority vote of the preferred stockholders for a period of 12 months (“Redemption Election Period”). If the holders of at least a majority of the preferred stock then outstanding did not approve the redemption of preferred shares outstanding during the Redemption Election Period, the Company would have had no further obligation to redeem any shares of preferred stock. Dividends were cumulative, but were payable only upon their redemption or the occurrence of a significant event that would result in a distribution to their holders of less than 110% of the shares’ liquidation value (generally the applicable gross issuance price of the shares). As of September 29, 2013, the Company classified the preferred stock outside of permanent equity on the balance sheet as redemption of the preferred stock was outside the control of the Company.
	The Company recognized changes in the redemption value immediately as they occurred via direct charges to additional paid-in capital and then to accumulated deficit, and adjusted the carrying value of the preferred stock to equal its maximum redemption value at the end of each reporting period. In the event of a redemption, the price paid by the Company for the preferred stock would be the greater of (a) the liquidation value of the preferred stock series being redeemed, plus any accrued and unpaid dividends, or (b) the amount in respect of such share of preferred stock that such holder would have been entitled to receive on an as-converted basis assuming all the shares have been converted into common stock. The form of consideration in the event of liquidation would be the same for the common stockholders as would be provided to the preferred stockholders. The redemption and conversion features do not require bifurcation and separate measurement in the financial statements since neither of the features meet the net settlement criteria under ASC Topic 815, Derivatives and Hedging.
	The Company measured its redeemable convertible preferred stock at its maximum redemption value at each reporting period. The fair value of the Company, used to calculate the maximum redemption value of the redeemable convertible preferred stock and to measure the value of the common stock as a key assumption in the determination of the compensation expense associated with the Company’s stock options, was determined with assistance from an independent third-party valuation specialist. The valuations of the Company and its common stock were determined based on valuation methodologies and assumptions selected in accordance with the guidelines outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Companies Equity Securities Issued as Compensation. In the absence of observable market data regarding the value of the Company’s stock, the valuation of the Company and its common stock was estimated using multiple valuation approaches, primarily an income and market approach. The income approach is based on the present value of estimated future cash flows, and relies upon significant assumptions and estimates, including those related to the selected discount rate and forecasted revenues and expenses. The market approach is based on a comparison to observed fair values of comparable peer companies and recent market transactions, adjusted for the relative size and profitability of these peer companies relative to the Company.
	As of September 29, 2013, each share of common stock had the same relative rights and was identical in all respects to each other share of common stock. Each holder of shares of common stock was entitled to one vote for each share held by such holder at all meetings of stockholders. As of September 29, 2013, each share of non-voting common stock had no voting rights. The terms of the non-voting common stock provided that all shares of non-voting common stock would convert into voting common stock on a 1:1 basis immediately prior to the closing of an underwritten IPO or sale of the Company. The redeemable convertible preferred stock included down-round provisions which would adjust the conversion price for any additional stock issued without consideration or for a consideration per share less than the respective conversion price for one or more of the series of preferred stock in effect immediately prior to the issuance of such additional stock.
	On February 26, 2013, the Company issued 59,865 stock options to Bryant Keil, the Company’s Founding Chairman and current member of the board of directors, which are exercisable without restriction and vested immediately. Subsequent to the issuance, the applicable conversion price for the Series D preferred stock and Series E preferred stock was adjusted under the conversion procedure provision in order to prevent dilution. After the adjustment, the Series D preferred stock and Series E preferred stock were convertible into common stock at the conversion rates of 1:1.03 and 1:1.03, respectively.
	On October 9, 2013, the Company completed an initial public offering. See Note 8, “Subsequent Events.” Effective upon the closing of such offering, all shares of preferred stock and non-voting common stock converted into common stock and all dividends accrued on the shares of preferred stock were forfeited.
	In August 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.
	On August 1, 2013, the Company’s board of directors unanimously approved a resolution to amend certain terms of the Company’s preferred stockholder agreements to reduce certain pricing thresholds for the completion of a qualified IPO, with such term defined in the agreements. The Company evaluated the impact of the amendments on the related preferred shares by estimating the fair value of such shares immediately prior to and after the amendments. As there was an insignificant change in the fair value of the preferred shares as a result of the amendments, the Company concluded the amendments represented a modification to the preferred share agreements. Therefore, no change in value was recorded in the condensed consolidated statement of redeemable convertible preferred stock and equity (deficit). In addition, the Company’s board of directors declared a cash dividend on August 1, 2013, in an aggregate amount of approximately $49.9 million on shares of the Company’s common and preferred stock outstanding on the day immediately prior to the closing date of the Company’s initial public offering. The dividend was recorded as an accrued dividend payable in the condensed consolidated balance sheet as of September 29, 2013 as substantive conditions for the initial public offering were met as of September 29, 2013. The Company paid the cash dividend on October 9, 2013 from the net proceeds of the Company’s initial public offering.

Stock_Options

Stock Options	9 Months Ended
	Sep. 29, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock Options	'
	(7) Stock Options
	2013 Long-Term Incentive Plan
	On July 31, 2013, the Company’s board of directors approved the adoption of the 2013 Long-Term Incentive Plan, which replaced the 2004 Incentive Plan in conjunction with the Company’s initial public offering. The Company will no longer make awards under the 2004 Incentive Plan. However, the 2004 Incentive Plan will continue to govern outstanding awards granted prior to its termination. As of September 29, 2013, there have been no options granted under the 2013 Long-Term Incentive Plan. The Company has 1,500,000 shares reserved for future issuance under the 2013 Long-Term Incentive Plan. See Note 8, “Subsequent Events” for options granted after September 29, 2013.
	Stock Options Granted Under the 2001 and 2004 Equity Incentive Plans
	The Company has granted stock options under its 2001 and 2004 Equity Incentive Plans (the “Plans”). The Plans permit the granting of awards to employees and nonemployee 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.
	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, upon the consummation of an IPO under the Securities Act or at the discretion of the board of directors. Certain options have been issued to key executives, which are exercisable without restriction. Options issued and outstanding expire on various dates through the year 2023. The range of exercise prices of options outstanding as of September 29, 2013, is $7 to $14 per option, and the options vest over a range of immediately to five-year periods.
	Under the 2001 Plan, the Company had 746,749 shares reserved for issuance. In September 2011, the 2001 Plan expired with options outstanding under the plan still available for exercise. As of December 30, 2012 and September 29, 2013, a total of 3,960,998 and 4,289,994 shares of common stock have been reserved for issuance under the 2004 Equity Incentive Plan and a total of 500,000 shares of non-voting common stock have been reserved for issuance under a Stock Option Agreement and Plan (the “Agreement”). In 2007, the Company entered into the Agreement, which granted a certain key executive 500,000 options of non-voting common stock.
	Activity under the Plans and the Agreement is as follows:
	Options	Shares			Weighted		Aggregate		Weighted
		(Thousands)			Average		Intrinsic		Average
					Exercise		Value		Remaining
					Price		(Thousands)		Term
									(Years)
	Outstanding—December 25, 2011		4,261			9.19	$	2,229		6.34
	Granted		504			8.65
	Exercised		—			—
	Canceled		(552	)		7.67
	Outstanding—December 30, 2012		4,213			9.3	$	5,348		5.93
	Granted		848			10.06
	Exercised		—			—
	Canceled		(316	)		8.4
	Outstanding—September 29, 2013		4,745			8.99	$	15,434		6.22
	On February 26, 2013, the Company issued 59,865 stock options to Bryant Keil, the Company’s Founding Chairman and current member of the board of directors, which are exercisable without restriction and vested immediately. The fair value of the options was determined using the Black-Scholes-Merton option pricing model. The Company used the following assumptions for purposes of valuing these option grants: common stock fair value of $9.47 per share; expected life of options—five years; volatility—46.6%; risk-free interest rate—0.8%; and dividend yield—0.0%. The Company used the simplified method for determining the expected life of the options. The Company was unable to calculate specific stock price volatility as a private company, and as such, the Company used a blended volatility rate for comparable publicly traded companies.
	On July 29, 2013, the Company entered into employment agreements with certain executives, including Charlie Talbot, its Chief Financial Officer, and John Morlock, its Senior Vice President of Operations. The terms of the agreements are substantially similar to one another and include compensation arrangements consistent with their current compensation arrangements as well as the acceleration of 278,272 unvested stock options under the 2004 Equity Plan, of which 141,341 options include a performance condition that restricts the option holders’ ability to exercise vested options until the consummation of an IPO under the Securities Act or at the discretion of the Company’s board of directors. Accordingly, all outstanding options are now fully vested as of the date of the executed agreements. In accordance with ASC Topic 718, Compensation – Stock Compensation, the Company does not expect to record an incremental charge related to the accelerated vesting of unvested options that do not contain a performance condition since the modification did not result in incremental value. The Company has estimated the potential compensation cost to be recorded upon consummation of an IPO associated with all vested options, including those modified to accelerate vesting, is approximately $7.5 million as of September 29, 2013.
	On August 1, 2013, the Company modified stock option agreements for all current employees and the Company’s Founding Chairman to revise the exercise price of $14.00 per option on 718,593 options to an exercise price of $10.59 per option and issued 122,271 stock options to the same Founding Chairman at an exercise price of $10.59 per option. All of these options contain a performance condition that restricts the option holders’ ability to exercise vested options until the consummation of an IPO under the Securities Act or at the discretion of the Company’s board of directors. In accordance with ASC Topic 718, Compensation – Stock Compensation, the Company expects to record a charge of approximately $0.7 million during the fourth quarter of 2013 related to the incremental value associated with the reduced exercise price at the time performance conditions have been met and a charge of approximately $0.6 million associated with options issued to the Founding Chairman at the time performance conditions have been met.
	On August 8, 2013, the Company entered into an employment agreement with Aylwin Lewis, its Chief Executive Officer and President. The agreement includes a compensation arrangement consistent with his current compensation arrangement as well as the grant of 227,187 options under the 2004 Equity Plan, which are exercisable without restriction and vest over a period of four years. In accordance with ASC Topic 718, Compensation – Stock Compensation, fair value of the options was determined using the Black-Scholes-Merton option pricing model. The Company used the following assumptions for purposes of valuing these option grants: common stock fair value of $10.59 per share; expected life of options—seven years; volatility—48.0%; risk-free interest rate—1.3%; and dividend yield—0.0%. The Company used the simplified method for determining the expected life of the options.
	On August 20, 2013, the Company issued 81,064 replacement stock options to Bryant Keil, under the 2004 Equity Plan, which are exercisable without restriction and vested immediately. The fair value of the options was determined using the Black-Scholes-Merton option pricing model. The Company used the following assumptions for purposes of valuing these option grants: common stock fair value of $10.59 per share; expected life of the options – five years; volatility – 48.0%; risk-free rate – 1.6%; and dividend yield – 0.0%. The Company used the simplified method for determining the expected life of the options. In accordance with ASC Topic 718,Compensation – Stock Compensation, the Company recorded a charge of $0.4 million related to these options.
	Stock-based Compensation
	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). For those options that are exercisable without restriction, the Company recognized $2.4 million and $2.3 million for the 39 weeks ended September 29, 2013 and for the 39 weeks ended September 23, 2012, respectively, with a corresponding increase to additional paid-in-capital. As of September 29, 2013, and September 23, 2012, the unrecognized stock compensation expense was $1.2 million and $2.1 million, respectively, which will be recognized through fiscal year 2018. The Company records stock based compensation expense within general and administrative expenses in the consolidated statements of operations.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 29, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	(8) Subsequent Events
	Initial Public Offering
	On October 9, 2013, the Company completed an initial public offering of 8,625,000 shares of common stock at a price of $14.00 per share, 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 estimated offering expenses. The Company did not receive any proceeds from the shares sold by the selling stockholders. Because the initial public offering was a qualified IPO, as defined, all outstanding preferred stock automatically converted into common stock upon the closing of the offering. All dividends accrued on the shares of preferred stock were forfeited at the time of such conversion. Additionally, all outstanding options to purchase non-voting common stock of the Company automatically converted into options to purchase common stock upon the closing of the initial public offering.
	Dividend Payment in Connection with Initial Public Offering
	The Company used the net proceeds received from the sale of its shares in the initial public offering to pay a previously declared cash dividend of approximately $49.9 million on shares outstanding on October 8, 2013.
	Debt Repayment in Connection with Initial Public Offering
	On October 24, 2013, the Company used $14.0 million of the net proceeds from the sale of its shares in the initial public offering to repay the amounts outstanding under the senior credit facility.
	Option Grants in Connection with Initial Public Offering
	Under the 2013 Long-Term Incentive Plan, the Company granted options to purchase 395,000 shares of the Company’s common stock, effective as of the closing of the Company’s initial public offering, to certain senior leaders. Such options have an exercise price equal to the initial public offering price of $14.00 per share and have a four year vesting period. The fair value of the options was determined using the Black-Scholes-Merton option pricing model. The Company used the following assumptions for purposes of valuing these option grants: common stock fair value of $14.00 per share; expected life of options—seven years; volatility—48.3%; risk-free interest rate—2.1%; and dividend yield—0.0%. The Company used the simplified method for determining the expected life of the options. The Company was unable to calculate specific stock price volatility as a private company, and as such, the Company used a blended volatility rate for comparable publicly traded companies.

Organization_and_Other_Matters1

Organization and Other Matters (Policies)	9 Months Ended
	Sep. 29, 2013
Accounting Policies [Abstract]	'
Business	'
	Business
	Potbelly Corporation (the “Company” or “Potbelly”), through its wholly owned subsidiary, Potbelly Sandwich Works LLC, operates Potbelly Sandwich Works sandwich shops in 18 states and the District of Columbia. As of December 30, 2012 and September 29, 2013, the Company had 264 and 288 company-operated shops, respectively. During fiscal year 2012, the Company opened 31 new shops and closed one shop. During the 39 weeks ended September 29, 2013, the Company opened 25 new shops and closed one shop.
	The Company also sells and administers franchises of new Potbelly Sandwich Works sandwich shops. The first domestic and international franchise locations administered by the Company opened during February 2011. As of the fiscal year ended 2012, five franchised shops were in operation domestically and ten franchised shops were in operation internationally. As of September 29, 2013, seven franchised shops were in operation in domestic locations and twelve franchised shops were in operation internationally.
	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 prospectus dated October 3, 2013, filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended (the “Securities Act”), with the Securities and Exchange Commission (“SEC”) on October 4, 2013. The unaudited condensed consolidated financial statements included herein have been prepared by the Company without audit, pursuant to the rules and regulations of the SEC regarding interim financial reporting. The December 30, 2012 condensed consolidated balance sheet was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (“GAAP”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the SEC’s rules and regulations, although management believes that the disclosures are adequate and make the information presented not misleading. 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 financial position as of December 30, 2012 and September 29, 2013, its statement of operations for the 13 weeks and 39 weeks ended September 23, 2012 and September 29, 2013 and its statement of cash flows for the 39 weeks ended September 23, 2012 and September 29, 2013 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 (loss) recorded within its consolidated financial statements, and, therefore, does not separately present a statement of comprehensive income (loss) in its consolidated 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, Potbelly Sandwich Works, LLC (“LLC”) and 17 of LLC’s wholly owned subsidiaries, collectively, the “Company.” All significant intercompany balances and transactions have been eliminated in consolidation. For the Company’s consolidated joint venture, non-controlling interest represents the non-controlling partner’s share of the assets, liabilities and operations related to the joint venture investment in Potbelly Airport II Boston, LLC, related to one shop located in the Boston Logan International Airport. The Company owns a seventy-five percent interest in this consolidated joint venture.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions, primarily related to long-lived assets, income taxes, stock-based compensation and common stock equity valuations, 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.
Fiscal Year	'
	Fiscal Year
	The Company uses a 52/53-week fiscal year that ends on the last Sunday of the calendar year. Approximately every six or seven years a 53rd week is added. Fiscal 2012 consisted of 53 weeks. The fiscal quarters ended September 23, 2012 and September 29, 2013 each consisted of 13 weeks and the fiscal year-to-date periods ended September 23, 2012 and September 29, 2013 each consisted of 39 weeks.
Stock based Compensation	'
	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). For those options that are exercisable without restriction, the Company recognized $2.4 million and $2.3 million for the 39 weeks ended September 29, 2013 and for the 39 weeks ended September 23, 2012, respectively, with a corresponding increase to additional paid-in-capital. As of September 29, 2013, and September 23, 2012, the unrecognized stock compensation expense was $1.2 million and $2.1 million, respectively, which will be recognized through fiscal year 2018. The Company records stock based compensation expense within general and administrative expenses in the consolidated statements of operations.

Earnings_per_share_Tables

Earnings per share (Tables)	9 Months Ended
	Sep. 29, 2013
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	'
		13 Weeks Ended						39 Weeks Ended
		September 29,			September 23,			September 29,			September 23,
		2013			2012			2013			2012
	Calculation of undistributed (loss) for basic and diluted shares:
	Net income attributable to Potbelly Corporation	$	2,165		$	2,548		$	4,941		$	5,571
	Less: Dividend declared to common and preferred stockholders		(49,854	)		—			(49,854	)		—
	Less: Accretion of redeemable convertible preferred stock to maximum redemption value		(4,796	)		(5,545	)		(15,097	)		(13,887	)
	Undistributed loss for basic and diluted shares	$	(52,485	)	$	(2,997	)	$	(60,010	)	$	(8,316	)
	Allocation of undistributed(loss) to participating securities:
	Common shares	$	(52,485	)	$	(2,997	)	$	(60,010	)	$	(8,316	)
	Redeemable convertible preferred shares		—			—			—			—
	Undistributed (loss) income	$	(52,485	)	$	(2,997	)	$	(60,010	)	$	(8,316	)
	Weighted average common shares outstanding-basic		4,268,953			3,972,873			4,250,819			3,972,873
	Plus: Effect of potential stock options exercise		—			—			—			—
	Plus: Effect of potential warrant exercise		—			—			—			—
	Weighted average common shares outstanding-diluted		4,268,953			3,972,873			4,250,819			3,972,873
	Income (loss) per share available to common stockholders-basic	$	(12.29	)	$	(0.75	)	$	(14.12	)	$	(2.09	)
	Income (loss) per share available to common stockholders-diluted	$	(12.29	)	$	(0.75	)	$	(14.12	)	$	(2.09	)
	Potentially dilutive shares that are considered anti-dilutive:
	Common share options		4,744,664			4,446,049			4,744,664			4,446,049
	Warrants		241,704			378,996			241,704			378,996

Longterm_debt_Tables

Long-term debt (Tables)	9 Months Ended
	Sep. 29, 2013
Debt Disclosure [Abstract]	'
Summary of Long Term Debt	'
	Long-term debt consisted of the following (in thousands):
		September 29,		December 30,
		2013		2012
	Senior credit facility (a)	$	14,000	$	14,000
	Note payable (b)		1,110		1,169
	Total long-term debt		15,110		15,169
	Less: Current portion		14,074		74
	Long-term debt, net of current portion	$	1,036	$	15,095

Capital_Stock_and_Warrants_Tab

Capital Stock and Warrants (Tables)	9 Months Ended
	Sep. 29, 2013
Equity [Abstract]	'
Summary of Issued Warrants	'
	A roll-forward of the Company’s issued warrants as of September 29, 2013 is set forth below:
	Unexercised Warrants		Number of
			Warrants
	Outstanding—December 25, 2011			378,996
	Issuance of warrants at $8.16 per share (a)			241,704
	Exercise of warrants at $5.46 per share			(261,104	)
	Outstanding—December 30, 2012			359,596
	Exercise of warrants at $0.01 per share			(117,892	)
	Outstanding—September 29, 2013			241,704
	(a)	As part of the initial investment by outside investors in 2001, the Company issued stock warrants convertible to 200,000 shares of common stock at an exercise price of $5.00 per share, which expired on September 1, 2011. After the expiration of these warrants and to recognize past and continued service to the board of directors, the Company issued an additional 241,704 warrants at an exercise price of $8.16 per share. The Company used the following assumptions for purposes of valuing these warrants granted in 2011: common stock fair value of $8.16 per share; expected life of warrants-five years; volatility-53.0%; risk-free interest rate-1.1%; and dividend yield-0.0%.

Stock_Options_Tables

Stock Options (Tables)	9 Months Ended
	Sep. 29, 2013
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			Weighted		Aggregate		Weighted
		(Thousands)			Average		Intrinsic		Average
					Exercise		Value		Remaining
					Price		(Thousands)		Term
									(Years)
	Outstanding—December 25, 2011		4,261			9.19	$	2,229		6.34
	Granted		504			8.65
	Exercised		—			—
	Canceled		(552	)		7.67
	Outstanding—December 30, 2012		4,213			9.3	$	5,348		5.93
	Granted		848			10.06
	Exercised		—			—
	Canceled		(316	)		8.4
	Outstanding—September 29, 2013		4,745			8.99	$	15,434		6.22

Organization_and_Other_Matters2

Organization and Other Matters - Additional Information (Detail)

Sep. 29, 2013

Oct. 09, 2013

Sep. 29, 2013

Dec. 30, 2012

Sep. 29, 2013

Dec. 30, 2012

Sep. 29, 2013

Dec. 30, 2012

Sep. 29, 2013

Dec. 30, 2012

Sep. 29, 2013

Dec. 30, 2012

State

IPO [Member]

Company Operated Shops [Member]

Company Operated Shops [Member]

Opened Shops [Member]

Opened Shops [Member]

Closed Shops [Member]

Closed Shops [Member]

First Franchise Locations [Member]

First Franchise Locations [Member]

First Franchise Locations [Member]

First Franchise Locations [Member]

Subsequent Event [Member]

Store

Store

Store

Store

Store

Store

Domestic Operations [Member]

Domestic Operations [Member]

International Operation [Member]

International Operation [Member]

Store

Store

Store

Store

Nature Of Business And Basis Of Presentation [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Number of sandwich works and shops operation states

18

'

'

'

'

'

'

'

'

'

'

'

Number of shops

'

'

288

264

25

31

1

1

7

5

12

10

Initial public offering of common stock

'

8,625,000

'

'

'

'

'

'

'

'

'

'

Initial public offering period

'

'On October 9, 2013, the Company completed an initial public offering of 8,625,000 shares of common stock.

'

'

'

'

'

'

'

'

'

'

Earnings_Per_Share_Schedule_of

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 $)	3 Months Ended		9 Months Ended
	Sep. 29, 2013	Sep. 23, 2012	Sep. 29, 2013	Sep. 23, 2012
Calculation of undistributed (loss) for basic and diluted shares:	'	'	'	'
Net income attributable to Potbelly Corporation	$2,165,000	$2,548,000	$4,941,000	$5,571,000
Less: Dividend declared to common and preferred stockholders	-49,854,000	'	-49,854,000	'
Less: Accretion of redeemable convertible preferred stock to maximum redemption value	-4,796,000	-5,545,000	-15,097,000	-13,887,000
Undistributed loss for basic and diluted shares	-52,485,000	-2,997,000	-60,010,000	-8,316,000
Allocation of undistributed (loss) to participating securities:	'	'	'	'
Undistributed (loss) income	-52,485	-2,997	-60,010	-8,316
Weighted average common shares outstanding-basic	4,268,953	3,972,873	4,250,819	3,972,873
Plus: Effect of potential stock options exercise	'	'	'	'
Plus: Effect of potential warrant exercise	'	'	'	'
Weighted average common shares outstanding-diluted	4,268,953	3,972,873	4,250,819	3,972,873
Income (loss) per share available to common stockholders-basic	($12.29)	($0.75)	($14.12)	($2.09)
Income (loss) per share available to common stockholders-diluted	($12.29)	($0.75)	($14.12)	($2.09)
Common Share Options [Member]	'	'	'	'
Allocation of undistributed (loss) to participating securities:	'	'	'	'
Potentially dilutive shares that are considered anti-dilutive	4,744,664	4,446,049	4,744,664	4,446,049
Common Stock [Member]	'	'	'	'
Allocation of undistributed (loss) to participating securities:	'	'	'	'
Undistributed (loss) income	($52,485)	($2,997)	($60,010)	($8,316)
Warrant [Member]	'	'	'	'
Allocation of undistributed (loss) to participating securities:	'	'	'	'
Potentially dilutive shares that are considered anti-dilutive	241,704	378,996	241,704	378,996

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 29, 2013	Sep. 23, 2012	Sep. 29, 2013	Sep. 23, 2012
Income Tax Disclosure [Abstract]	'	'	'	'
Income tax expense	$905	$84	$2,792	$765
Pre-tax income	$3,079	$2,637	$7,757	$6,301
Effective tax rate	'	'	36.00%	12.10%

Longterm_Debt_Summary_of_Long_

Long-term Debt - Summary of Long Term Debt (Detail) (USD $)	Sep. 29, 2013	Dec. 30, 2012
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'	'
Senior credit facility	$14,000	$14,000
Note payable	1,110	1,169
Total long-term debt	15,110	15,169
Less: Current portion	14,074	74
Long-term debt, net of current portion	$1,036	$15,095

Longterm_Debt_Additional_Infor

Long-term Debt - Additional Information (Detail) (USD $)	9 Months Ended		1 Months Ended	9 Months Ended		1 Months Ended
	Sep. 29, 2013	Sep. 23, 2012	Sep. 21, 2012	Sep. 29, 2013	Dec. 30, 2012	Oct. 24, 2013
	Note Payable [Member]	Note Payable [Member]	JPMorgan Chase Bank, N.A. [Member]	JPMorgan Chase Bank, N.A. [Member]	JPMorgan Chase Bank, N.A. [Member]	Subsequent Event [Member]
			Senior credit facility [Member]	Senior credit facility [Member]	Senior credit facility [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'
Public offering proceeds used for repayments of debt	'	'	'	'	'	$14,000,000
Revolving credit facility agreement term period	'	'	'5 years	'	'	'
Revolving credit facility agreement expiration date	'	'	'	30-Sep-17	'	'
Borrowings allowed to fund capital expenditures	'	'	35,000,000	'	'	'
Maximum leverage ratio	'	'	2.25	'	'	'
Minimum debt service coverage ratio	'	'	1.5	'	'	'
Federal funds effective rate plus	'	'	'	0.50%	'	'
Federal funds base rate	'	'	'	'The base rate is the higher of the prime rate and the federal funds rate, plus 0.50%.	'	'
Weighted average interest rate	'	'	'	1.35%	1.35%	'
Interest rate on notes payable under effective interest rate method	6.00%	6.00%	'	'	'	'
Interest expense on note payable	$54,000	$57,000	'	'	'	'

Capital_Stock_and_Warrants_Add

Capital Stock and Warrants - Additional Information (Detail) (USD $)

1 Months Ended

9 Months Ended

1 Months Ended

In Thousands, except Share data, unless otherwise specified

Aug. 31, 2013

Sep. 29, 2013

Sep. 23, 2012

Dec. 30, 2012

Feb. 26, 2013

Sep. 29, 2013

Dec. 30, 2012

Sep. 29, 2013

Dec. 30, 2012

Sep. 29, 2013

Dec. 30, 2012

Sep. 29, 2013

Dec. 30, 2012

Sep. 29, 2013

Feb. 26, 2013

Dec. 30, 2012

Sep. 29, 2013

Feb. 26, 2013

Dec. 30, 2012

Sep. 29, 2013

Dec. 30, 2012

Board Of Directors [Member]

Non-voting Common Stock [Member]

Non-voting Common Stock [Member]

Series A Preferred Stock [Member]

Series A Preferred Stock [Member]

Series B Preferred Stock [Member]

Series B Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series D Preferred Stock [Member]

Series D Preferred Stock [Member]

Series D Preferred Stock [Member]

Series E Preferred Stock [Member]

Series E Preferred Stock [Member]

Series E Preferred Stock [Member]

Series F Preferred Stock [Member]

Series F Preferred Stock [Member]

Class Of Warrant And Capital Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capital stock, authorized

'

52,683,632

'

52,683,632

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, authorized

'

35,500,000

'

35,500,000

'

500,000

500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, issued

'

4,351,869

'

4,233,977

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, outstanding

'

4,351,869

'

4,233,977

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred stock, authorized

'

17,183,632

'

17,183,632

'

'

'

4,197,377

4,197,377

3,375,221

3,375,221

1,666,668

1,666,668

1,250,000

'

1,250,000

4,194,366

'

4,194,366

2,500,000

2,500,000

Preferred stock, issued

'

16,086,375

'

16,086,375

'

'

'

3,697,377

'

3,290,294

'

1,646,595

'

1,250,000

'

'

4,194,366

'

'

2,007,743

'

Preferred stock, outstanding

'

16,086,375

'

16,086,375

'

'

'

3,697,377

'

3,290,294

'

1,646,595

'

1,250,000

'

'

4,194,366

'

'

2,007,743

'

Preferred stock dividend rate

'

6.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum percentage of liquidation value to be paid

'

110.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of liquidation value to be paid

'

'Dividends were cumulative, but were payable only upon their redemption or the occurrence of a significant event that would result in a distribution to their holders of less than 110% of the shares' liquidation value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Terms of non-voting Common stock conversion basis ratio

'

'The terms of the non-voting common stock provided that all shares of non-voting common stock would convert into voting common stock on a 1:1 basis immediately prior to the closing of an underwritten IPO or sale of the Company.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock conversion ratio

'

1

'

'

'

'

'

'

'

'

'

'

'

'

1.03

'

'

1.03

'

'

'

Stock options issued

'

'

'

'

59,865

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Modification of warrants issued

241,704

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Recognized stock compensation expense

$100

$2,370

$2,320

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash dividend declared

'

$49,854

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Date of cash dividend paid

'

9-Oct-13

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capital_Stock_and_Warrants_Sum

Capital Stock and Warrants - Summary of Issued Warrants (Detail)	9 Months Ended	12 Months Ended
	Sep. 29, 2013	Dec. 30, 2012
Equity [Abstract]	'	'
Unexercised Warrants Outstanding	359,596	378,996
Issuance of warrants	'	241,704
Less: Exercise of warrants	-117,892	-261,104
Unexercised Warrants Outstanding	241,704	359,596

Capital_Stock_and_Warrants_Sum1

Capital Stock and Warrants - Summary of Issued Warrants (Parenthetical) (Detail) (USD $)	0 Months Ended	12 Months Ended
	Sep. 19, 2001	Dec. 30, 2012	Sep. 29, 2013
Equity [Abstract]	'	'	'
Number of shares convertible under warrant	200,000	'	'
Exercise price of warrants	'	$8.16	'
Exercise price of warrants	5	5.46	0.01
Common stock fair value	'	$8.16	'
Fair value assumption, expected life of warrants	'	'5 years	'
Volatility	'	53.00%	'
Fair value assumption, risk-free interest rate	'	1.10%	'
Fair value assumption, dividend yield	'	0.00%	'
Common stock warrant, expiration date	1-Sep-11	'	'

Stock_Options_Additional_Infor

Stock Options - Additional Information (Detail) (USD $)

1 Months Ended

9 Months Ended

12 Months Ended

0 Months Ended

0 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

0 Months Ended

2 Months Ended

Aug. 31, 2013

Sep. 29, 2013

Sep. 23, 2012

Dec. 30, 2012

Sep. 29, 2013

Aug. 01, 2013

Aug. 01, 2013

Aug. 01, 2013

Aug. 01, 2013

Sep. 29, 2013

Sep. 29, 2013

Sep. 29, 2013

Sep. 29, 2013

Sep. 29, 2013

Sep. 29, 2013

Sep. 29, 2013

Dec. 30, 2012

Jul. 29, 2013

Sep. 29, 2013

Jul. 29, 2013

Aug. 20, 2013

Aug. 08, 2013

Feb. 26, 2013

Sep. 29, 2013

Common Share Options [Member]

Employees And Board Members [Member]

Employees And Board Members [Member]

Board Of Director [Member]

Board Of Director [Member]

Non-voting Common Stock [Member]

Scenario, Forecast [Member]

Scenario, Forecast [Member]

2001 and 2004 Equity Incentive Plans [Member]

2001 and 2004 Equity Incentive Plans [Member]

2001 Equity Incentive Plans [Member]

2004 Equity Incentive Plans [Member]

2004 Equity Incentive Plans [Member]

2004 Equity Plan [Member]

2004 Equity Plan [Member]

2004 Equity Plan [Member]

2004 Equity Plan [Member]

2004 Equity Plan [Member]

February 26, 2013 [Member]

2013 Long-Term Incentive Plan [Member]

Performance Shares [Member]

Performance Shares [Member]

Performance Shares [Member]

Board Of Director [Member]

Maximum [Member]

Management [Member]

Management [Member]

Management [Member]

Board Of Directors [Member]

Chief Executive Officer [Member]

Board Of Directors [Member]

Performance Shares [Member]

Performance Shares [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options available for grant

'

848,000

'

504,000

'

'

718,593

'

122,271

'

'

'

'

'

'

'

'

278,272

'

141,341

81,064

227,187

59,865

0

Shares of common stock reserved for issuance

'

'

'

'

500,000

'

'

'

'

'

'

'

'

'

746,749

4,289,994

3,960,998

'

'

'

'

'

'

1,500,000

Exercisable period from the date of grant

'

'

'

'

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

Options issued and outstanding, last expiration date

'

'

'

'

'

'

'

'

'

'

'

'

'

31-Dec-23

'

'

'

'

'

'

'

'

'

'

Exercise price of options outstanding, lower limit

'

'

'

'

'

'

'

'

'

'

'

'

$7

'

'

'

'

'

'

'

'

'

'

'

Exercise price of options outstanding, higher limit

'

'

'

'

'

'

'

'

'

'

'

'

$14

'

'

'

'

'

'

'

'

'

'

'

Options vesting period

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

'4 years

'

'

Shares of common stock issued to key executive

'

'

'

'

'

'

'

'

'

500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Method used to determine fair value of the options

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'Black-Scholes-Merton option pricing model

'Black-Scholes-Merton option pricing model

'Black-Scholes-Merton option pricing model

'

Common stock fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$10.59

$10.59

$9.47

'

Expected life of options

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'7 years

'5 years

'

Volatility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

48.00%

48.00%

46.60%

'

Risk-free interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.56%

1.30%

0.80%

'

Dividend yield

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.00%

0.00%

0.00%

'

Estimated stock based compensation expense

'

'

'

'

'

'

'

'

'

'

$700,000

$600,000

'

'

'

'

'

'

$7,500,000

'

'

'

'

'

Price per option

'

'

'

'

'

$14

'

$10.59

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Recognized stock compensation expense

100,000

2,370,000

2,320,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

400,000

'

'

'

Unrecognized stock compensation expense

'

$1,200,000

$2,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecognized stock compensation expense, recognition period

'

'Through 2018

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock_Options_Summary_of_Activ

Stock Options - Summary of Activity Under Plans and Agreement (Detail) (USD $)	9 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 29, 2013	Dec. 30, 2012	Dec. 25, 2011
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'	'
Options Outstanding shares, Granted	848	504	'
Options Outstanding shares, Exercised	'	'	'
Options Outstanding shares, Canceled	-316	-552	'
Options Outstanding shares, ending balance	4,745	4,213	4,261
Options outstanding weighted average exercise price, Granted	$10.06	$8.65	'
Options outstanding weighted average exercise price, Exercised	'	'	'
Options outstanding weighted average exercise price, Canceled	$8.40	$7.67	'
Options outstanding weighted average exercise price, ending balance	$8.99	$9.30	$9.19
Options Outstanding Aggregate Intrinsic value	$15,434	$5,348	$2,229
Option Outstanding Weighted Average Remaining Term	'6 years 2 months 19 days	'5 years 11 months 5 days	'6 years 4 months 2 days

Subsequent_Event_Additional_In

Subsequent Event - Additional Information (Detail) (USD $)	9 Months Ended	12 Months Ended		2 Months Ended	1 Months Ended		1 Months Ended
	Sep. 29, 2013	Dec. 30, 2012	Sep. 23, 2012	Sep. 29, 2013	Oct. 24, 2013	Oct. 08, 2013	Oct. 09, 2013	Oct. 09, 2013	Oct. 09, 2013	Oct. 09, 2013
				2013 Long-Term Incentive Plan [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]	IPO [Member]	IPO [Member]	IPO [Member]
							2013 Long-Term Incentive Plan [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]
									Underwritten Public Offering [Member]	Shareholders' Equity [Member]
Subsequent Event [Line Items]	'	'	'	'	'	'	'	'	'	'
Public offering shares of common stock	'	'	'	'	'	'	'	8,625,000	1,125,000	'
Common stock issued, price per share	'	'	'	'	'	'	'	$14	'	'
Share sold by company	'	'	'	'	'	'	'	8,474,869	'	'
Share sold by stock holders through public offering	'	'	'	'	'	'	'	'	'	150,131
Net proceeds from IPO	'	'	'	'	'	'	'	$108,800,000	'	'
Cash dividend paid from proceeds from IPO	49,854,000	'	'	'	'	49,900,000	'	'	'	'
Public offering proceeds used for repayments of debt	'	'	'	'	$14,000,000	'	'	'	'	'
Number of shares available for grant	848,000	504,000	'	0	'	'	395,000	'	'	'
Vesting period	'	'	'	'	'	'	'4 years	'	'	'
Fair value of option grant	'	'	'	'	'	'	$14	'	'	'
Expected life of option	'	'	'	'	'	'	'7 years	'	'	'
Expected Volatility Rate	'	'	'	'	'	'	48.30%	'	'	'
Risk free interest rate	'	'	'	'	'	'	2.01%	'	'	'
Dividend yield	'	'	'	'	'	'	0.00%	'	'	'