Document and Entity Information Document	6 Months Ended
Document and Entity Information Document	Jun. 30, 2015	Aug. 03, 2015 Common Class A [Member]	Aug. 03, 2015 Common Class B [Member]
Document Information [Line Items]
Entity Registrant Name	NOODLES & Co
Entity Central Index Key	0001275158
Current Fiscal Year End Date	--12-29
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		26,847,602	1,522,098

Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2015	Dec. 30, 2014
Current assets:
Cash and cash equivalents	$ 2,001	$ 1,906
Accounts receivable	4,311	5,184
Inventories	9,909	9,415
Prepaid expenses and other assets	6,954	6,271
Total current assets	23,175	22,776
Property and equipment, net	208,780	205,573
Goodwill	1,971	1,927
Goodwill	6,400	6,400
Other assets, net	2,360	2,227
Total long-term assets	219,511	216,127
Total assets	242,686	238,903
Current liabilities:
Accounts payable	11,364	10,865
Accrued payroll and benefits	5,422	4,704
Accrued expenses and other current liabilities	10,346	8,560
Current deferred tax liabilities, net	1,702	1,702
Total current liabilities	28,834	25,831
Long-term debt	29,922	27,500
Deferred rent	38,809	35,498
Deferred tax liabilities, net	4,968	6,512
Other long-term liabilities	3,532	3,447
Total liabilities	106,065	98,788
Stockholders' equity:
Preferred stock—$0.01 par value, authorized 1,000,000 shares as of June 30, 2015 and December 30, 2014; no shares issued or outstanding	0	0
Common stock—$0.01 par value, authorized 180,000,000 shares as of June 30, 2015 and December 30, 2014; 30,005,350 issued and 29,598,110 outstanding as of June 30, 2015 and 29,820,340 issued and outstanding as of December 30, 2014.	300	298
Treasury stock, at cost, 474,826 and 67,586 shares as of June 30, 2015 and December 30, 2014, respectively	(9,131)	(2,848)
Additional paid-in capital	123,418	120,929
Accumulated other comprehensive loss	(12)	0
Retained earnings	22,046	21,736
Total stockholders' equity	136,621	140,115
Total liabilities and stockholders' equity	$ 242,686	$ 238,903

Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2015	Dec. 30, 2014
Preferred stock, par value (USD per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized	180,000,000	180,000,000
Common stock, shares, issued	30,005,350	29,820,340
Common stock, shares, outstanding	29,598,100	29,820,340
Treasury stock, shares	474,826	67,586

Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jul. 01, 2014	Jun. 30, 2015	Jul. 01, 2014
Revenue:
Restaurant revenue	$ 113,834	$ 98,197	$ 218,616	$ 186,646
Franchising royalties and fees	1,399	1,262	2,378	2,333
Total revenue	115,233	99,459	220,994	188,979
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Cost of sales	29,863	26,326	57,674	50,174
Labor	35,149	29,328	68,178	56,526
Occupancy	12,480	10,245	24,698	20,110
Other restaurant operating costs	15,158	12,243	29,875	24,449
General and administrative	9,232	8,251	17,650	15,261
Depreciation and amortization	6,923	5,905	13,843	11,515
Pre-opening	1,162	1,027	2,042	2,140
Restaurant impairment, asset disposals and closure costs	250	193	6,336	408
Total costs and expenses	110,217	93,518	220,296	180,583
Income from operations	5,016	5,941	698	8,396
Interest expense	198	36	427	56
Income before income taxes	4,818	5,905	271	8,340
Provision (benefit) for income taxes	1,756	2,378	(39)	3,389
Net income	$ 3,062	$ 3,527	$ 310	$ 4,951
Earnings per share of Class A and Class B common stock, combined:
Basic (USD per share)	$ 0.10	$ 0.12	$ 0.01	$ 0.17
Diluted (USD per share)	$ 0.10	$ 0.11	$ 0.01	$ 0.16
Weighted average shares of Class A and Class B common stock outstanding, combined:
Basic (in shares)	29,950,122	29,703,884	29,896,663	29,655,102
Diluted (in shares)	30,720,102	31,063,774	30,792,278	31,061,722

Consolidated Statements of Comprehensive Income Statement (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jul. 01, 2014	Jun. 30, 2015	Jul. 01, 2014
Net income	$ 3,062	$ 3,527	$ 310	$ 4,951
Cash flow hedges:
Foreign currency translation adjustments	(1)	0	(12)	0
Other comprehensive loss	(1)	0	(12)	0
Comprehensive income	$ 3,061	$ 3,527	$ 298	$ 4,951

Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2015	Jul. 01, 2014
Operating activities
Net income	$ 310	$ 4,951
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	13,843	11,515
Deferred income taxes	(1,544)	3,389
Restaurant impairment, asset disposals and closure costs	6,296	408
Amortization of debt issuance costs	49	51
Stock-based compensation	625	665
Changes in operating assets and liabilities:
Accounts receivable	242	69
Inventories	(473)	(1,039)
Prepaid expenses and other assets	(754)	(1,957)
Accounts payable	(329)	651
Deferred rent	3,322	2,797
Income taxes	1,130	(163)
Accrued expenses and other liabilities	(61)	(2,226)
Net cash provided by operating activities	22,656	19,111
Investing activities
Purchases of property and equipment	(21,861)	(24,459)
Acquisition of franchise restaurants	(628)	0
Net cash used in investing activities	(22,489)	(24,459)
Financing activities
Proceeds from issuance of long-term debt	182,326	128,971
Payments on long-term debt	(179,904)	(125,654)
Debt issuance costs	(111)	0
Acquisition of treasury stock	(4,136)	(71)
Other financing activities	(27)	(60)
Other financing activities	1,792	1,904
Net cash (used in) provided by financing activities	(60)	5,090
Effect of Exchange Rate on Cash and Cash Equivalents	(12)	0
Net increase (decrease) in cash and cash equivalents	95	(258)
Cash and cash equivalents
Beginning of period	1,906	968
End of period	$ 2,001	$ 710

Business and Summary and Basis of Presentation	6 Months Ended
Business and Summary and Basis of Presentation	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Summary and Basis of Presentation	Business Summary and Basis of Presentation Business Noodles & Company, (the "Company" or "Noodles & Company"), a Delaware corporation, develops and operates fast casual restaurants that serve globally inspired noodle and pasta dishes, soups, salads and sandwiches. As of June 30, 2015, there were 411 company-owned restaurants and 61 franchise restaurants located in 35 states, the District of Columbia and one Canadian province. The Company operates its business as one operating and reportable segment. The accompanying interim unaudited consolidated financial statements have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (the "SEC"). Accordingly, they do not include all the information and footnotes required by generally accepted accounting principles in the United States ("U.S. GAAP") for complete financial statements. In the opinion of the Company, all adjustments considered necessary for the fair presentation of the Company's results of operations, financial position and cash flows for the periods presented have been included and are of a normal, recurring nature. The results of operations for interim periods are not necessarily indicative of the results to be expected for the full year. These financial statements should be read in conjunction with the audited financial statements and the related notes included in the Company's Annual Report on Form 10-K for the fiscal year ended December 30, 2014. Principles of Consolidation The accompanying consolidated financial statements include the accounts of Noodles & Company and its subsidiaries. All material intercompany balances and transactions are eliminated in consolidation. Fiscal Year The Company operates on a 52- or 53-week fiscal year ending on the Tuesday closest to December 31. Fiscal year 2015, which ends on December 29, 2015, and fiscal year 2014, which ended on December 30, 2014, each contain 52 weeks. Fiscal quarters each contain thirteen weeks, with the exception of the fourth quarter of a 53-week fiscal year, which contains fourteen weeks. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, "Revenue from Contracts with Customers (Topic 606)." The pronouncement was issued to clarify the principles for recognizing revenue and to develop a common revenue standard and disclosure requirements for U.S. GAAP and International Financial Reporting Standards. The pronouncement is effective for annual and interim periods beginning after December 15, 2017, which will require the Company to adopt these provisions in the first quarter of fiscal 2018. Early adoption is not permitted. This pronouncement permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect this guidance will have on the Company's consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting. In August 2014, the FASB issued ASU No. 2014-15, "Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern." This update requires management of the Company to evaluate whether there is substantial doubt about the Company’s ability to continue as a going concern. This update is effective for the annual period ending after December 15, 2016, and for annual and interim periods thereafter. Early adoption is permitted. The Company does not expect this standard to have an impact on the Company’s consolidated financial statements. In April 2015, the FASB issued ASU No. 2015-03, "Interest-Imputation of Interest (Subtopic 835-50): Simplifying the Presentation of Debt Issuance Costs." This update requires debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a direct deduction from the carrying value of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this update. The update is effective retrospectively for fiscal years, and interim periods within those years, beginning after December 15, 2015. Early adoption is permitted. The adoption of this standard is not expected to have a material effect on the Company's consolidated financial statements. 1. Business Summary and Basis of Presentation (continued) In April 2015, the FASB issued ASU No. 2015-05, "Intangibles - Goodwill and Other-Internal-use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement." The pronouncement was issued to provide guidance concerning accounting for fees in a cloud computing arrangement. The update is effective for reporting periods beginning after December 15, 2015. The adoption of this standard is not expected to have a material effect on the Company's consolidated financial statements.

Borrowings	6 Months Ended
Borrowings	Jun. 30, 2015
Debt Disclosure [Abstract]
Borrowings	On June 4, 2015, the Company amended its existing credit facility to increase borrowing capacity on the revolving line of credit from $45.0 million to $75.0 million and to extend its term from November 2018 to June 2020. All other material terms and covenants remained the same. As of June 30, 2015, the Company had $29.9 million outstanding and $42.3 million available for borrowing under the credit facility. Outstanding letters of credit aggregating $2.8 million reduce the amount available to borrow. The credit facility bore interest at 3.50% during the first two quarters of 2015. The Company was in compliance with all of its debt covenants as of June 30, 2015.

Fair Value Measurements	6 Months Ended
Fair Value Measurements	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and all other current liabilities approximate their fair values due to the short maturities of these instruments. The carrying amounts of borrowings approximate fair value as interest rates on the the line of credit borrowings vary with market interest rates and negotiated terms and conditions are consistent with current market rates. The fair value of our line of credit borrowings is measured using Level 2 inputs. Adjustments to the fair value of non-financial assets measured at fair value on a non-recurring basis as of June 30, 2015 are discussed in Note 8-Restaurant Impairments, Asset Disposals and Closure Costs. There were no adjustments to the fair values of non-financial assets measured at fair value on a non-recurring basis as of July 1, 2014.

Income Taxes

6 Months Ended

Jun. 30, 2015

Income Tax Disclosure [Abstract]

Income Taxes

The following table presents the Company's provision (benefit) for income taxes for the first two quarters ended June 30, 2015 and July 1, 2014 (dollars in thousands):



	Fiscal Quarter Ended						Two Fiscal Quarters Ended
	June 30, 2015			July 1, 2014			June 30, 2015			July 1, 2014
Provision (benefit) for income taxes	$	1,756		$	2,378		$	(39	)	$	3,389
Effective tax rate	36.5		%	40.3		%	14.3		%	40.6		%

The effective tax rate for the second quarter of 2015 and the first two quarters of 2015 reflects a projected federal tax rate of 34%, compared to 35% for the second quarter of 2014 and the first two quarters of 2014, as well as a discrete benefit for additional employment tax credits in the second quarter of 2015. The 2015 estimated annual effective tax rate is expected to be between 39% and 40% compared to 38.4% for 2014 due to an increase in estimated non-deductible expenses.

Share Repurchase (Notes)	6 Months Ended
Share Repurchase (Notes)	Jun. 30, 2015
Equity [Abstract]
Share Repurchases	Share Repurchases On June 4, 2015, the Company announced a share repurchase program of up to $35.0 million of the Company's Class A common stock. Under this program, which expires June 4, 2016, the Company may, from time to time, purchase shares of the Company's Class A common stock in the open market (including in pre-arranged stock trading plans in accordance with the guidelines specified in Rule 10b5-1 under the Securities Exchange Act of 1934, as amended ) or in privately negotiated transactions. During the second quarter ended June 30, 2015, the Company repurchased 407,240 shares of its common stock for approximately $6.3 million in open market transactions. As of June 30, 2015, the remaining dollar value of authorization under the share repurchase program was $28.7 million. Repurchased shares are included as treasury stock in the Condensed Consolidated Balance Sheets.

Stock-Based Compensation

6 Months Ended

Jun. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

The Company's Stock Incentive Plan, as amended and restated in May of 2013, authorizes the grant of nonqualified stock options, incentive stock options, stock appreciation rights, restricted stock, restricted stock units and incentive bonuses to employees, officers, non-employee directors and other service providers. The number of shares of common stock available for issuance pursuant to awards granted under the Stock Incentive Plan shall not exceed 3,750,500.

The following table presents information related to the Stock Incentive Plan (in thousands, except share and per share amounts):



	Fiscal Quarter Ended				Two Fiscal Quarters Ended
	June 30, 2015		July 1, 2014		June 30, 2015		July 1, 2014
Outstanding, beginning of period	3,225,078		3,157,914		3,245,264		3,309,872
Granted	351,305		231,552		527,321		231,552
Exercised	52,664		50,989		175,551		193,238
Forfeited	5,034		13,655		78,349		23,364
Outstanding, end of period	3,518,685		3,324,822		3,518,685		3,324,822
Weighted average fair market value on option grant date	$	5.81	$	10.93	$	5.95	$	10.93
Stock based compensation expense	$	512	$	536	$	699	$	694
Capitalized stock based compensation expense	$	59	$	29	$	99	$	12

Asset Disposals, Closure Costs and Restaurant Impairments (Notes)

6 Months Ended

Jun. 30, 2015

Property, Plant and Equipment Impairment or Disposal [Abstract]

Restaurant Impairments, Asset Disposals and Closure Costs

The following table presents restaurant impairments, asset disposals and closure costs for the first two quarters ended June 30, 2015 and July 1, 2014 (in thousands):



	Fiscal Quarter Ended				Two Fiscal Quarters Ended
	June 30, 2015		July 1, 2014		June 30, 2015		July 1, 2014
Restaurant impairments ⁽¹⁾	$	31	$	—	$	5,944	$	5
Loss on disposal of assets	187		146		321		281
Closure costs and other ⁽¹⁾	32		47		71		122
	$	250	$	193	$	6,336	$	408

_____________________________


(1)	Restaurant impairments and closure costs can include expenditures related to restaurants previously impaired or closed.

During the first two quarters of 2015, the Company recognized restaurant impairment expense of $5.9 million, primarily related to management's current assessment of the expected future cash flows at eight restaurants, based on recent results. Impairment expense is a Level 3 fair value measure and was determined by comparing the carrying value of restaurant assets to the estimated fair market value, which is based on projected cash flows. Fair value is generally determined based on appraisals or sales prices of comparable assets and estimates of future cash flows. These expenses are included in the "Restaurant impairment, asset disposals and closure costs" line in the Consolidated Statements of Income.

Earnings Per Share

6 Months Ended

Jun. 30, 2015

Earnings Per Share [Abstract]

Earnings Per Share

Earnings per share ("EPS") is calculated by dividing income available to common stockholders by the weighted-average number of shares of common stock outstanding during each period. Diluted earnings per share ("diluted EPS") is calculated using income available to common stockholders divided by diluted weighted-average shares of common stock outstanding during each period. Potentially dilutive securities include shares of common stock underlying stock options and warrants.

The following table sets forth the computations of basic and diluted earnings per share:



	Fiscal Quarter Ended				Two Fiscal Quarters Ended
	June 30, 2015		July 1, 2014		June 30, 2015		July 1, 2014
Net income (in thousands):	$	3,062	$	3,527	$	310	$	4,951
Shares:
Basic weighted average shares outstanding	29,950,122		29,703,884		29,896,663		29,655,102
Dilutive stock options and warrants	769,980		1,359,890		895,615		1,406,620
Diluted weighted average number of shares outstanding	30,720,102		31,063,774		30,792,278		31,061,722
Earnings per share:
Basic EPS	$	0.10	$	0.12	$	0.01	$	0.17
Diluted EPS	$	0.10	$	0.11	$	0.01	$	0.16

In the second quarters of 2015 and 2014, there were 1,214,159 and 243,552 outstanding options, respectively, excluded from the diluted earnings per share calculation because they were anti-dilutive. In the first two quarters of 2015 and 2014, there were 809,711 and 243,552 outstanding options, respectively, excluded from the diluted earnings per share calculation because they were anti-dilutive.

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies In the normal course of business, the Company is subject to other proceedings, lawsuits and claims, including those matters that the Company has previously disclosed and for which there is no material update. Consequently, the Company is unable to ascertain the ultimate aggregate amount of monetary liability or financial impact with respect to these matters as of June 30, 2015. These matters could affect the operating results of any one financial reporting period when resolved in future periods. Management believes that an unfavorable outcome with respect to these matters is remote or a potential range of loss is not material to the Company's consolidated financial statements. Significant increases in the number of these claims, or one or more successful claims that result in greater liabilities than the Company currently anticipates, could materially and adversely affect the Company's business, financial condition, results of operations or cash flows.

Business and Summary and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements include the accounts of Noodles & Company and its subsidiaries. All material intercompany balances and transactions are eliminated in consolidation.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, "Revenue from Contracts with Customers (Topic 606)." The pronouncement was issued to clarify the principles for recognizing revenue and to develop a common revenue standard and disclosure requirements for U.S. GAAP and International Financial Reporting Standards. The pronouncement is effective for annual and interim periods beginning after December 15, 2017, which will require the Company to adopt these provisions in the first quarter of fiscal 2018. Early adoption is not permitted. This pronouncement permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect this guidance will have on the Company's consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting. In August 2014, the FASB issued ASU No. 2014-15, "Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern." This update requires management of the Company to evaluate whether there is substantial doubt about the Company’s ability to continue as a going concern. This update is effective for the annual period ending after December 15, 2016, and for annual and interim periods thereafter. Early adoption is permitted. The Company does not expect this standard to have an impact on the Company’s consolidated financial statements. In April 2015, the FASB issued ASU No. 2015-03, "Interest-Imputation of Interest (Subtopic 835-50): Simplifying the Presentation of Debt Issuance Costs." This update requires debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a direct deduction from the carrying value of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this update. The update is effective retrospectively for fiscal years, and interim periods within those years, beginning after December 15, 2015. Early adoption is permitted. The adoption of this standard is not expected to have a material effect on the Company's consolidated financial statements.

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Compensation, Stock Options, Activity

The following table presents information related to the Stock Incentive Plan (in thousands, except share and per share amounts):



	Fiscal Quarter Ended				Two Fiscal Quarters Ended
	June 30, 2015		July 1, 2014		June 30, 2015		July 1, 2014
Outstanding, beginning of period	3,225,078		3,157,914		3,245,264		3,309,872
Granted	351,305		231,552		527,321		231,552
Exercised	52,664		50,989		175,551		193,238
Forfeited	5,034		13,655		78,349		23,364
Outstanding, end of period	3,518,685		3,324,822		3,518,685		3,324,822
Weighted average fair market value on option grant date	$	5.81	$	10.93	$	5.95	$	10.93
Stock based compensation expense	$	512	$	536	$	699	$	694
Capitalized stock based compensation expense	$	59	$	29	$	99	$	12

Asset Disposals, Closure Costs and Restaurant Impairments (Tables)

6 Months Ended

Jun. 30, 2015

Property, Plant and Equipment Impairment or Disposal [Abstract]

Impaired Assets to be Disposed of by Method Other than Sale

The following table presents restaurant impairments, asset disposals and closure costs for the first two quarters ended June 30, 2015 and July 1, 2014 (in thousands):



	Fiscal Quarter Ended				Two Fiscal Quarters Ended
	June 30, 2015		July 1, 2014		June 30, 2015		July 1, 2014
Restaurant impairments ⁽¹⁾	$	31	$	—	$	5,944	$	5
Loss on disposal of assets	187		146		321		281
Closure costs and other ⁽¹⁾	32		47		71		122
	$	250	$	193	$	6,336	$	408

Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2015

Earnings Per Share [Abstract]

Schedule of Earnings Per Share

The following table sets forth the computations of basic and diluted earnings per share:



	Fiscal Quarter Ended				Two Fiscal Quarters Ended
	June 30, 2015		July 1, 2014		June 30, 2015		July 1, 2014
Net income (in thousands):	$	3,062	$	3,527	$	310	$	4,951
Shares:
Basic weighted average shares outstanding	29,950,122		29,703,884		29,896,663		29,655,102
Dilutive stock options and warrants	769,980		1,359,890		895,615		1,406,620
Diluted weighted average number of shares outstanding	30,720,102		31,063,774		30,792,278		31,061,722
Earnings per share:
Basic EPS	$	0.10	$	0.12	$	0.01	$	0.17
Diluted EPS	$	0.10	$	0.11	$	0.01	$	0.16

Business and Summary and Basis of Presentation (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2015 segment province state	Dec. 30, 2014
Franchisor Disclosure [Line Items]
Number of states in which Noodles & Company operates	35
Number of Canadian provinces	1
Number of operating segments	1
Number of reportable segments	1
Common stock, par value (USD per share)	$ 0.01	$ 0.01
Number of weeks in fiscal year	364 days	364 days
Company-Owned [Member]
Franchisor Disclosure [Line Items]
Number of restaurants	411
Franchise [Member]
Franchisor Disclosure [Line Items]
Number of restaurants	61

Supplemental Financial Information (Property and Equipment) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2015	Dec. 30, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 348,625	$ 334,900
Accumulated depreciation and amortization	(139,845)	(129,327)
Property and equipment, net	208,780	205,573
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	217,493	208,678
Furniture, Fixtures, and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	119,478	114,148
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 11,654	$ 12,074

Borrowings (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015
Line of Credit Facility [Line Items]
Amount outstanding	$ 29.9	$ 29.9
Remaining borrowing capacity	42.3	42.3
Letters of credit outstanding	$ 2.8	$ 2.8
Minimum [Member]
Line of Credit Facility [Line Items]
Interest rate	3.50%	3.50%

Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jul. 01, 2014	Jun. 30, 2015	Jul. 01, 2014	Dec. 30, 2014
Income Tax Contingency [Line Items]
Provision (benefit) for income taxes	$ 1,756	$ 2,378	$ (39)	$ 3,389
Effective tax rate	36.50%	40.30%	14.30%	40.60%
Income tax rate	34.00%	35.00%
Estimated effective tax rate					38.00%
Minimum [Member]
Income Tax Contingency [Line Items]
Estimated effective tax rate	39.00%		39.00%
Maximum [Member]
Income Tax Contingency [Line Items]
Estimated effective tax rate	40.00%		40.00%

Share Repurchase (Details) (Common Class A [Member], USD $)	3 Months Ended
	Jun. 30, 2015	Jun. 04, 2015
Common Class A [Member]
Equity, Class of Treasury Stock [Line Items]
Share repurchase program amount		$ 35,000,000.0
Treasury shares acquired in period (in shares)	407,240
Value of treasury stock acquired	6,300,000
Remaining amount of shares to be purchased	$ 28,700,000

Stock-Based Compensation (Stock Incentive Plan) (Details) (Stock Option [Member], USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jul. 01, 2014	Jun. 30, 2015	Jul. 01, 2014
Stock Option [Member]
Options, Outstanding [Roll Forward]
Outstanding, beginning of period	3,225,078	3,157,914	3,245,264	3,309,872
Granted	351,305	231,552	527,321	231,552
Exercised	52,664	50,989	175,551	193,238
Forfeited	5,034	13,655	78,349	23,364
Outstanding, end of period	3,518,685	3,324,822	3,518,685	3,324,822
Weighted average fair market value on option grant date	$ 5.81	$ 10.93	$ 5.95	$ 10.93
Stock based compensation expense	$ 512	$ 536	$ 699	$ 694
Capitalized stock based compensation expense	$ 59	$ 29	$ 99	$ 12

Asset Disposals, Closure Costs and Restaurant Impairments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015 restaurant	Jul. 01, 2014	Jun. 30, 2015 restaurant	Jul. 01, 2014
Property, Plant and Equipment Impairment or Disposal [Abstract]
Restaurant impairments	$ 31	$ 0	$ 5,944	$ 5
Loss on disposal of assets	187	146	321	281
Closure costs and other	32	47	71	122
Total	$ 250	$ 193	$ 6,336	$ 408
Number of restaurants	8		8

Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jul. 01, 2014	Jun. 30, 2015	Jul. 01, 2014
Earnings Per Share [Abstract]
Net income	$ 3,062	$ 3,527	$ 310	$ 4,951
Shares:
Basic weighted average shares outstanding (in shares)	29,950,122	29,703,884	29,896,663	29,655,102
Dilutive stock options and warrants (in shares)	769,980	1,359,890	895,615	1,406,620
Diluted weighted average number of shares outstanding (in shares)	30,720,102	31,063,774	30,792,278	31,061,722
Earnings per share:
Basic EPS (USD per share)	$ 0.10	$ 0.12	$ 0.01	$ 0.17
Diluted EPS (USD per share)	$ 0.10	$ 0.11	$ 0.01	$ 0.16
Antidilutive securities excluded from computation of earnings per share	1,214,159	243,552	809,711	243,552

Supplemental Disclosures to Consolidated Statements of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2015	Jul. 01, 2014
Supplemental Cash Flow Elements [Abstract]
Interest paid (net of amounts capitalized)	$ 571	$ 0
Income taxes paid	376	163
Changes in purchases of property and equipment accrued in accounts payable, net	$ 827	$ (204)

Stock-Based Compensation (Narrative) (Details) (IPO [Member])	May 31, 2013
IPO [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Maximum shares reserved for issuance	3,750,500

Acquisition of Franchised Restaurants (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2015	Dec. 30, 2014
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill	$ 6,400	$ 6,400