Shake Shack (SHAK) 10-Q 7 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 28, 2021
Document Information [Line Items]
Security Exchange Name	NYSE
Trading Symbol	SHAK
Title of 12(b) Security	Class A Common Stock, par value $0.001
Entity Interactive Data Current	Yes
Local Phone Number	747-7200
City Area Code	646
Entity Address, Postal Zip Code	10014
Entity Tax Identification Number	47-1941186
Entity Incorporation, State or Country Code	DE
Entity File Number	001-36823
Document Transition Report	false
Document Quarterly Report	true
Document type	10-Q
Amendment flag	false
Document Period End Date	Mar. 31, 2021
Document fiscal year focus	2021
Document fiscal period focus	Q1
Entity registrant name	SHAKE SHACK INC.
Entity Address, Address Line One	225 Varick Street
Entity Address, Address Line Two	Suite 301
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity central index key	0001620533
Current fiscal year end date	--12-29
Entity filer category	Large Accelerated Filer
Entity current reporting status	Yes
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Class A Common Stock
Document Information [Line Items]
Entity common stock, shares outstanding (in shares)		39,103,614
Class B Common Stock
Document Information [Line Items]
Entity common stock, shares outstanding (in shares)		2,921,588

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 30, 2020
Current assets:
Cash and cash equivalents	$ 374,999	$ 146,873
Marketable securities	40,914	36,887
Accounts receivable, net	8,838	9,464
Inventories	2,734	2,888
Prepaid expenses and other current assets	7,805	7,074
Total current assets	435,290	203,186
Property and equipment, net of accumulated depreciation of $179,226 and $166,156, respectively	348,580	336,541
Operating lease assets	312,087	306,317
Deferred income taxes, net	299,838	287,007
Other assets	11,794	12,297
TOTAL ASSETS	1,407,589	1,145,348
Current liabilities:
Accounts payable	24,307	23,487
Accrued expenses	28,774	25,920
Accrued wages and related liabilities	13,306	10,441
Operating lease liabilities, current	37,275	35,657
Other current liabilities	15,087	14,200
Total current liabilities	118,749	109,705
Long-term debt	242,875	0
Long-term operating lease liabilities	349,670	343,736
Liabilities under tax receivable agreement, net of current portion	234,048	232,954
Other long-term liabilities	22,297	24,460
Total liabilities	967,639	710,855
Commitments and contingencies (Note 13)
Stockholders' equity:
Preferred stock, no par value—10,000,000 shares authorized; none issued and outstanding as of March 31, 2021 and December 30, 2020.	0	0
Additional paid-in capital	400,371	395,067
Retained earnings	13,518	12,209
Accumulated other comprehensive income	2	3
Total stockholders' equity attributable to Shake Shack Inc.	413,933	407,321
Non-controlling interests	26,017	27,172
Total equity	439,950	434,493
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	1,407,589	1,145,348
Class A Common Stock
Stockholders' equity:
Common stock	39	39
Class B Common Stock
Stockholders' equity:
Common stock	$ 3	$ 3

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENT OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
TOTAL REVENUE	$ 155,282	$ 143,170
Shack-level operating expenses:
Food and paper costs	44,630	39,564
Labor and related expenses	46,382	41,766
Other operating expenses	23,144	17,779
Occupancy and related expenses	13,911	12,558
General and administrative expenses	19,565	16,191
Depreciation and amortization expense	13,726	11,768
Pre-opening costs	3,576	2,243
Impairment and loss on disposal of assets	369	2,088
TOTAL EXPENSES	165,303	143,957
OPERATING LOSS	(10,021)	(787)
Other income (expense), net	31	(93)
Interest expense	(515)	(112)
LOSS BEFORE INCOME TAXES	(10,505)	(992)
Income tax expense (benefit)	(11,080)	87
NET INCOME (LOSS)	575	(1,079)
Reallocation of net loss attributable to non-controlling interests from the assumed conversion of Class B shares	(734)	(119)
NET INCOME (LOSS) ATTRIBUTABLE TO SHAKE SHACK INC.	$ 1,309	$ (960)
Earnings (loss) per share of Class A common stock:
Basic (in dollars per share)	$ 0.03	$ (0.03)
Diluted (in dollars per share)	$ 0.01	$ (0.03)
Weighted-average shares of Class A common stock outstanding:
Basic (in shares)	38,948	34,444
Diluted (in shares)	42,789	34,444
Shack sales
TOTAL REVENUE	$ 150,668	$ 138,048
Licensing revenue
TOTAL REVENUE	$ 4,614	$ 5,122

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss) attributable to Shake Shack Inc.—basic	$ 575	$ (1,079)
Other comprehensive income (loss), net of tax(1):
Change in foreign currency translation adjustment	(1)	1
Net change	(1)	1
OTHER COMPREHENSIVE INCOME (LOSS)	(1)	1
COMPREHENSIVE INCOME (LOSS)	574	(1,078)
Less: comprehensive loss attributable to non-controlling interest	(734)	(119)
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO SHAKE SHACK INC.	$ 1,308	$ (959)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (Parenthetical) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Statement of Comprehensive Income [Abstract]
Income tax benefit	$ 0	$ 0

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Class A Common Stock	Class B Common Stock	Common Stock [Member]Class A Common Stock	Common Stock [Member]Class B Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non- Controlling Interest
Beginning balance (shares) at Dec. 25, 2019				34,417,302	3,145,197
Beginning balance at Dec. 25, 2019	$ 321,985			$ 35	$ 3	$ 244,410	$ 54,367	$ 2	$ 23,168
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to Shake Shack Inc.—basic	(1,079)						(960)		(119)
Other comprehensive income (loss):
Net change in foreign currency translation adjustment	1							1
Equity-based compensation	1,313					1,313
Activity under stock compensation plans (in shares)				77,903
Activity under stock compensation plans	63					424			(361)
Redemption of LLC Interests (in shares)				28,195	28,195
Stock Issued During Period, Value, Conversion of Units	0			$ 0	$ 0	195			195
Establishment of liabilities under tax receivable agreement and related changes to deferred tax assets associated with increases in tax basis	628					628
Distributions paid to non-controlling interest holders	(305)								(305)
Ending balance (shares) at Mar. 25, 2020				34,523,400	3,117,002
Ending balance at Mar. 25, 2020	322,606			$ 35	$ 3	246,970	53,407	3	22,188
Beginning balance (shares) at Dec. 30, 2020		38,717,790	2,951,188	38,717,790	2,951,188
Beginning balance at Dec. 30, 2020	434,493			$ 39	$ 3	395,067	12,209	3	27,172
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to Shake Shack Inc.—basic	575						1,309		(734)
Other comprehensive income (loss):
Net change in foreign currency translation adjustment	(1)							(1)
Equity-based compensation	1,696					1,696
Activity under stock compensation plans (in shares)				355,849
Activity under stock compensation plans	3,441					3,359			82
Redemption of LLC Interests (in shares)				29,600	29,600
Stock Issued During Period, Value, Conversion of Units	0					36			36
Establishment of liabilities under tax receivable agreement and related changes to deferred tax assets associated with increases in tax basis	213					213
Distributions paid to non-controlling interest holders	(467)								(467)
Ending balance (shares) at Mar. 31, 2021		39,103,239	2,921,588	39,103,239	2,921,588
Ending balance at Mar. 31, 2021	$ 439,950			$ 39	$ 3	$ 400,371	$ 13,518	$ 2	$ 26,017

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
OPERATING ACTIVITIES
Net income (loss) (including amounts attributable to non-controlling interests)	$ 575	$ (1,079)
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Depreciation and amortization expense	13,726	11,768
Amortization of debt issuance costs	86	0
Capitalized Computer Software, Amortization	313	260
Non-cash operating lease cost	12,330	10,742
Equity-based compensation	1,681	1,300
Deferred income taxes	(1,523)	3,775
Non-cash interest expense	337	69
Gain on sale of marketable securities	0	(79)
Impairment and loss on disposal of assets	369	2,088
Unrealized loss on available-for-sale securities	46	356
Other non-cash (income) expense	(1)	183
Changes in operating assets and liabilities:
Accounts receivable	626	3,150
Inventories	154	306
Prepaid expenses and other current assets	(731)	(439)
Other assets	(216)	(1,039)
Accounts payable	1,474	(4,449)
Accrued expenses	(9,420)	(6,330)
Accrued wages and related liabilities	2,865	(5,113)
Other current liabilities	(158)	273
Long-term operating lease liabilities	(10,754)	(8,755)
Other long-term liabilities	(1,828)	497
NET CASH PROVIDED BY OPERATING ACTIVITIES	9,951	7,484
INVESTING ACTIVITIES
Purchases of property and equipment	(23,155)	(19,159)
Purchases of marketable securities	(4,073)	(192)
Sales of marketable securities	0	20,000
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(27,228)	649
FINANCING ACTIVITIES
Proceeds from issuance of convertible notes, net of discount	243,750	0
Proceeds from revolving credit facility	0	50,000
Deferred financing costs	(70)	0
Payments on principal of finance leases	(602)	(615)
Distributions paid to non-controlling interest holders	(467)	(305)
Payments under tax receivable agreement	0	(6,569)
Debt issuance costs	(649)	0
Proceeds from stock option exercises	6,451	1,032
Payment, Tax Withholding, Share-based Payment Arrangement	(3,010)	(969)
NET CASH PROVIDED BY FINANCING ACTIVITIES	245,403	42,574
NET INCREASE IN CASH AND CASH EQUIVALENTS	228,126	50,707
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	146,873	37,099
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 374,999	$ 87,806

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	3 Months Ended
	Mar. 31, 2021
Supplemental Cash Flow Elements [Abstract]
SUPPLEMENTAL CASH FLOW INFORMATION	SUPPLEMENTAL CASH FLOW INFORMATION The following table sets forth supplemental cash flow information for the thirteen weeks ended March 31, 2021 and March 25, 2020: Thirteen Weeks Ended March 31 March 25 Cash paid for: Income taxes, net of refunds $ 388 $ 801 Interest, net of amounts capitalized 70 61 Non-cash investing activities: Accrued purchases of property and equipment 12,949 13,715 Capitalized equity-based compensation 9 13 Non-cash financing activities: Revolving Credit Facility amendment-related accrual 112 — Convertible Notes issuance-related accrual 312 — Establishment of liabilities under tax receivable agreement 1,094 310

SUPPLEMENTAL CASH FLOW INFORM_2

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2021
Supplemental Cash Flow Elements [Abstract]
Schedule of Cash Flow Information	The following table sets forth supplemental cash flow information for the thirteen weeks ended March 31, 2021 and March 25, 2020: Thirteen Weeks Ended March 31 March 25 Cash paid for: Income taxes, net of refunds $ 388 $ 801 Interest, net of amounts capitalized 70 61 Non-cash investing activities: Accrued purchases of property and equipment 12,949 13,715 Capitalized equity-based compensation 9 13 Non-cash financing activities: Revolving Credit Facility amendment-related accrual 112 — Convertible Notes issuance-related accrual 312 — Establishment of liabilities under tax receivable agreement 1,094 310

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 30, 2020
Preferred Stock, no par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Less: accumulated depreciation	$ 179,226	$ 166,156
Class A Common Stock
Common stock par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares, issued (in shares)	39,103,239	38,717,790
Common stock, shares, outstanding (in shares)	39,103,239	38,717,790
Class B Common Stock
Common stock par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	35,000,000	35,000,000
Common stock, shares, issued (in shares)	2,921,588	2,951,188
Common stock, shares, outstanding (in shares)	2,921,588	2,951,188

SUPPLEMENTAL CASH FLOW INFORM_3

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Cash paid for:
Income taxes, net of refunds	$ 388	$ 801
Interest, net of amounts capitalized	70	61
Non-cash investing activities:
Accrued purchases of property and equipment	12,949	13,715
Capitalized equity-based compensation	9	13
Non-cash financing activities:
Revolving Credit Facility amendment-related accrual	112	0
Convertible Notes issuance-related accrual	312	0
Establishment of liabilities under tax receivable agreement	$ 1,094	$ 310

NATURE OF OPERATIONS

NATURE OF OPERATIONS	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
NATURE OF OPERATIONS	NATURE OF OPERATIONSShake Shack Inc. was formed on September 23, 2014 as a Delaware corporation for the purpose of facilitating an initial public offering and other related transactions in order to carry on the business of SSE Holdings, LLC and its subsidiaries ("SSE Holdings"). We are the sole managing member of SSE Holdings and, as sole managing member, we operate and control all of the business and affairs of SSE Holdings. As a result, we consolidate the financial results of SSE Holdings and report a non-controlling interest representing the economic interest in SSE Holdings held by the other members of SSE Holdings. As of March 31, 2021 we owned 93.0% of SSE Holdings. Unless the context otherwise requires, "we," "us," "our," "Shake Shack," the "Company" and other similar references, refer to Shake Shack Inc. and, unless otherwise stated, all of its subsidiaries, including SSE Holdings.We operate and license Shake Shack restaurants ("Shacks"), which serve hamburgers, hot dogs, chicken, crinkle-cut fries, shakes, frozen custard, beer, wine and more. As of March 31, 2021, there were 321 Shacks in operation, system-wide, of which 192 were domestic Company-operated Shacks, 22 were domestic licensed Shacks and 107 were international licensed Shacks. As of March 31, 2021, four domestic Company-operated Shacks and 16 licensed Shacks were temporarily closed, primarily due to the COVID-19 pandemic.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of Shake Shack Inc. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. These interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") and on a basis consistent in all material respects with the accounting policies described in our Annual Report on Form 10-K for the fiscal year ended December 30, 2020 ("2020 Form 10-K"). Certain information and footnote disclosures normally presented in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes thereto included in our 2020 Form 10-K. In our opinion, all adjustments, which are normal and recurring in nature, necessary for a fair presentation of our financial position and results of operation have been included. Operating results for interim periods are not necessarily indicative of the results that may be expected for a full fiscal year. SSE Holdings is considered a variable interest entity. Shake Shack Inc. is the primary beneficiary as we have the majority economic interest in SSE Holdings and, as the sole managing member, have decision making authority that significantly affects the economic performance of the entity, while the limited partners have no substantive kick-out or participating rights. As a result, we consolidate SSE Holdings. The assets and liabilities of SSE Holdings represent substantially all of our consolidated assets and liabilities with the exception of certain deferred taxes and liabilities under the Tax Receivable Agreement. As of March 31, 2021 and December 30, 2020, the net assets of SSE Holdings were $380,713 and $383,669, respectively. The assets of SSE Holdings are subject to certain restrictions in SSE Holdings' revolving credit agreement. See Note 6, Debt, for more information. Fiscal Year We operate on a 52/53 week fiscal year ending on the last Wednesday in December. Fiscal 2021 contains 52 weeks and ends on December 29, 2021. Fiscal 2020 contained 53 weeks and ended on December 30, 2020. Unless otherwise stated, references to years in this report relate to fiscal years. Use of Estimates The preparation of these condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of sales and expenses during the reporting period. Actual results could differ from those estimates. Recently Adopted Accounting Pronouncements We adopted the Accounting Standards Updates (“ASUs”) summarized below in fiscal 2021. Accounting Standards Update Description Date Simplifying the Accounting for Income Taxes (ASU 2019-12) This standard simplifies various aspects related to accounting for income taxes by removing certain exceptions to the general principles in ASC 740, “Income Taxes” (“ASC 740”), and clarifying certain aspects of the current guidance to promote consistency among reporting entities. The adoption of this standard did not have a material impact to our condensed consolidated financial statements. December 31, 2020 Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity's Own (ASU 2020-06) This ASU amends the guidance on convertible instruments and the derivatives scope exception for contracts in an entity’s own equity and improves and amends the related earnings per share guidance for both Subtopics. We elected to early adopt this standard, beginning December 31, 2020. The guidance of this ASU is applicable to our convertible notes issued in March 2021. As a result, the convertible notes are accounted for as a single liability measured at amortized cost. The if-converted earnings per share ("EPS") method is used, with the effect of potential share settlement included in diluted EPS. Refer to Note 6, Debt, for further details of the convertible notes issued. December 31, 2020

REVENUE

REVENUE	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE Revenue Recognition Revenue consists of Shack sales and Licensing revenue. Generally, revenue is recognized as promised goods or services transfer to the guest or customer in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Shack revenues are recognized when payment is tendered at the point of sale as the performance obligation has been satisfied. Revenue from Shack sales is presented net of discounts and recognized when food, beverage and retail products are sold. Sales tax collected from customers is excluded from Shack sales and the obligation is included in sales tax payable until the taxes are remitted to the appropriate taxing authorities. Revenue from our gift cards is deferred and recognized upon redemption. Licensing revenues include initial territory fees, Shack opening fees, and ongoing sales-based royalty fees from licensed Shacks. Generally, the licenses granted to develop, open and operate each Shack in a specified territory are the predominant goods or services transferred to the licensee in our contracts, and represent distinct performance obligations. Ancillary promised services, such as training and assistance during the initial opening of a Shack, are typically combined with the licenses and considered as one performance obligation per Shack. We determine the transaction price for each contract, which is comprised of the initial territory fee, and an estimate of the total Shack opening fees we expect to be entitled to. The calculation of total Shack opening fees included in the transaction price requires judgment, as it is based on an estimate of the number of Shacks we expect the licensee to open. The transaction price is then allocated equally to each Shack expected to open. The performance obligations are satisfied over time, starting when a Shack opens, through the end of the term of the license granted to the Shack. Because we are transferring licenses to access our intellectual property during a contractual term, revenue is recognized on a straight-line basis over the license term. Generally, payment for the initial territory fee is received upon execution of the licensing agreement, and payment for the Shack opening fees are received either in advance of or upon opening the related Shack. These payments are initially deferred and recognized as revenue as the performance obligations are satisfied, which occurs over a long-term period. Revenue from sales-based royalties is recognized as the related sales occur. Revenue recognized during the thirteen weeks ended March 31, 2021 and March 25, 2020, disaggregated by type is as follows: Thirteen Weeks Ended March 31 March 25 Shack sales $ 150,668 $ 138,048 Licensing revenue: Sales-based royalties 4,425 4,944 Initial territory and opening fees 189 178 Total revenue $ 155,282 $ 143,170 The aggregate amount of the transaction price allocated to performance obligations that are unsatisfied (or partially unsatisfied) as of March 31, 2021 was $16,748. We expect to recognize this amount as revenue over a long-term period, as the license term for each Shack ranges from 5 to 20 years. This amount excludes any variable consideration related to sales-based royalties. Contract Balances Opening and closing balances of contract liabilities and receivables from contracts with customers is as follows: March 31 December 31 Shack sales receivables $ 5,641 $ 5,373 Licensing receivables, net of allowance for doubtful accounts 2,420 2,647 Gift card liability 2,600 2,637 Deferred revenue, current 612 608 Deferred revenue, long-term 11,965 12,151 Revenue recognized during the thirteen weeks ended March 31, 2021 and March 25, 2020 that was included in their respective liability balances at the beginning of the period is as follows: Thirteen Weeks Ended March 31 March 25 Gift card liability $ 219 $ 300 Deferred revenue 181 175

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Assets and Liabilities Measured at Fair Value on a Recurring Basis The carrying value of our Cash and cash equivalents, Accounts receivable, net, Accounts payable and Accrued expenses approximate their fair value due to the short-term nature of these financial instruments. As of March 31, 2021 and December 30, 2020, we held certain assets that are required to be measured at fair value on a recurring basis including our Marketable securities, which consist of investments in equity securities. Fair value of these investments is measured using Level 1 inputs (unadjusted quoted prices in active markets for identical assets). The carrying value of these investments in equity securities approximates fair value. Our assets measured at fair value on a recurring basis as of March 31, 2021 and December 30, 2020 were as follows: Fair Value Measurements March 31 December 30 Level 1 Level 1 Equity securities: Mutual funds $ 40,914 $ 36,887 Total Marketable securities $ 40,914 $ 36,887 Refer to Note 6, Debt, for the fair value of the Company's outstanding debt instruments. A summary of Other income (expense) from equity securities recognized during the thirteen weeks ended March 31, 2021 and March 25, 2020 is as follows: Thirteen Weeks Ended March 31 March 25 Equity securities: Dividend income $ 74 $ 184 Realized gain (loss) on sale of investments — 79 Unrealized gain (loss) on equity securities (46) (356) Total $ 28 $ (93) Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis Assets and liabilities that are measured at fair value on a non-recurring basis include our long-lived assets, operating lease right-of-use assets and indefinite-lived intangible assets. During the thirteen weeks ended March 25, 2020, we recognized an impairment charge of $1,132 at one location. Of the total impairment charge, $736 was attributed to property and equipment held and used, $383 was attributed to operating lease right-of-use assets, and $13 was attributed to finance lease right-of-use assets. The asset impairment charge was included in Impairment and loss on disposal of assets on the Condensed Consolidated Statement of Income (Loss). The fair values of assets were determined using an income-based approach and are classified as Level 3 within the fair value hierarchy. Significant inputs include projections of future cash flows, discount rates, Shack sales and profitability. There were no impairment charges recognized during the thirteen weeks ended March 31, 2021.

SUPPLEMENTAL BALANCE SHEET INFO

SUPPLEMENTAL BALANCE SHEET INFORMATION	3 Months Ended
	Mar. 31, 2021
Supplemental Balance Sheet Disclosures [Abstract]
SUPPLEMENTAL BALANCE SHEET INFORMATION	SUPPLEMENTAL BALANCE SHEET INFORMATION The components of Other current liabilities as of March 31, 2021 and December 30, 2020 are as follows: March 31 December 30 Sales tax payable $ 4,045 $ 4,285 Gift card liability 2,600 2,637 Current portion of financing equipment lease liabilities 2,445 1,998 Other 5,997 5,280 Other current liabilities $ 15,087 $ 14,200 The components of Other long-term liabilities as of March 31, 2021 and December 30, 2020 are as follows: March 31 December 30 Deferred licensing revenue $ 11,965 $ 12,151 Long-term portion of financing equipment lease liabilities 4,056 3,586 Other (1) 6,276 8,723 Other long-term liabilities $ 22,297 $ 24,460 (1) As of March 31, 2021, Other included $3,359 of deferred lease incentive liabilities related to leases with variable lease cost as well as $2,607 of deferred Social Security taxes associated with the Coronavirus Aid, Relief, and Economic Security Act.

DEBT

DEBT	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
DEBT	DEBT Revolving Credit Facility In August 2019, we entered into a revolving credit facility agreement ("Revolving Credit Facility"), which permits borrowings up to $50,000, of which the entire amount is available immediately, with the ability to increase available borrowings up to an additional $100,000, to be made available subject to satisfaction of certain conditions. The Revolving Credit Facility also permits the issuance of letters of credit upon our request of up to $15,000. In March 2020, we drew down the full $50,000 available under the Revolving Credit Facility to enhance liquidity and financial flexibility given the uncertain market conditions created by the COVID-19 pandemic. We repaid this amount in full, plus interest, in June 2020. In May 2020, we entered into a first amendment to the Revolving Credit Facility ("First Amendment"), which, among other things, provided for modified financial covenant compliance requirements for a period of time. The First Amendment required us to maintain minimum liquidity of $25,000 through July 1, 2021 and outstanding borrowings during the applicable period covered by the First Amendment bore interest at either: (i) the London Interbank Offered Rate ("LIBOR") plus a percentage ranging from 1.0% to 2.5% or (ii) the base rate plus a percentage ranging from 0.0% to 1.5%, in each case depending on our net lease adjusted leverage ratio. In March 2021, we entered into a second amendment to the Revolving Credit Facility (“Second Amendment”). The Second Amendment modified the applicable covenants and restrictions in the Credit Agreement to permit the incurrence of the Convertible Notes (as defined below), including obligations and transactions in connection therewith. In addition, the Second Amendment, among other things, (i) extended the period applicable to the increased interest rate margin as set forth in the First Amendment; (ii) shortened the maturity date of the Revolving Credit Facility from August 2024 to September 2022 and (iii) added mechanics relating to the transition from the use of LIBOR to the Secured Overnight Financing Rate ("SOFR") upon the discontinuance or unavailability of LIBOR. Subsequently, and also in March 2021, we entered into a third amendment to the Revolving Credit Facility (“Third Amendment”) with JPMorgan Chase Bank, N.A. (as successor agent to Wells Fargo Bank, National Association), as administrative agent, and the lenders party thereto. In addition, in March 2021, Wells Fargo Bank resigned as administrative agent under the Revolving Credit Facility and assigned its commitments thereunder to JPMorgan Bank, N.A. The Third Amendment appoints JPMorgan Bank, N.A. as administrative agent under the Revolving Credit Facility. In addition, the Third Amendment, among other things, extends the maturity date of the Revolving Credit Facility from September 2022 to March 2026. As of March 31, 2021 and December 30, 2020, no amounts were outstanding under the Revolving Credit Facility. The obligations under the Revolving Credit Facility are secured by a first-priority security interest in substantially all of the assets of SSE Holdings and the guarantors. The obligations under the Revolving Credit Facility are guaranteed by each of SSE Holdings' direct and indirect subsidiaries (with certain exceptions). The Revolving Credit Facility requires us to comply with maximum net lease adjusted leverage and minimum fixed charge coverage ratios. We are not subject to these coverage ratios for a period of time due to the Second Amendment to the Revolving Credit Facility described above. In addition, the Revolving Credit Facility contains other customary affirmative and negative covenants, including those which (subject to certain exceptions and dollar thresholds) limit our ability to incur debt; incur liens; make investments; engage in mergers, consolidations, liquidations or acquisitions; dispose of assets; make distributions on or repurchase equity securities; engage in transactions with affiliates; and prohibits us, with certain exceptions, from engaging in any line of business not related to our current line of business. As of March 31, 2021, we were in compliance with all covenants. As of March 31, 2021, the Revolving Credit Facility had unamortized deferred financing costs of $110, and was included in Other assets on the Condensed Consolidated Balance Sheet. Total interest expense related to the Revolving Credit Facility were $368 and $52 for the thirteen weeks ended March 31, 2021 and March 25, 2020, respectively. Total interest expense for the thirteen weeks ended March 31, 2021 primarily included write-off of previously capitalized costs on the Revolving Credit Facility. Convertible Notes In March 2021, we issued $225,000 aggregate principal amount of 0% Convertible Senior Notes due 2028 (the “Convertible Notes”) in a private placement to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933. We granted an option to the initial purchasers to purchase up to an additional $25,000 aggregate principal amount of Convertible Notes to cover over-allotments, which was subsequently fully exercised during March 2021, resulting in a total issuance of $250,000 aggregate principal amount of Convertible Notes. The Convertible Notes will mature on March 1, 2028, unless earlier converted, redeemed or repurchased in certain circumstances. Upon conversion, we pay or deliver, as the case may be, cash, shares of Shake Shack’s Class A common stock or a combination of cash and shares of Shake Shack’s Class A common stock, at our election. The Convertible Notes are convertible at the option of the holders at any time prior to the close of business on the business day immediately preceding December 1, 2027, only under the following circumstances: (1) during any fiscal quarter commencing after the fiscal quarter ending on June 30, 2021 (and only during such fiscal quarter), if the last reported sale price of our Class A common stock, par value $0.001 per share, for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding fiscal quarter is greater than or equal to 130% of the conversion price for the Convertible Notes on each applicable trading day; (2) during the five business day period after any ten consecutive trading day period (the “measurement period”) in which the trading price (as defined in the Indenture) per $1,000 principal amount of the Convertible Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of Class A common stock and the conversion rate for the Convertible Notes on each such trading day; (3) if we call such Convertible Notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date, but only with respect to the Convertible Notes called (or deemed called) for redemption; and (4) upon the occurrence of specified corporate events as set forth in the Indenture. On or after December 1, 2027, until the close of business on the second scheduled trading day immediately preceding the maturity date, holders of the Convertible Notes may convert all or any portion of their Convertible Notes at any time, regardless of the foregoing circumstances. The Convertible Notes had an initial conversion rate of 5.8679 shares of Shake Shack’s Class A common stock per $1,000 principal amount of Convertible Notes, which is equivalent to an initial conversion price of approximately $170.42 per share of Shake Shack’s Class A common stock. We may not redeem the Convertible Notes prior to March 6, 2025. We may redeem for cash all or any portion of the Convertible Notes, at our option, on or after March 6, 2025 if the last reported sale price of Shake Shack’s Class A common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day immediately preceding the date on which we provide notice of redemption at a redemption price equal to 100% of the principal amount of the Convertible Notes to be redeemed, plus accrued and unpaid special interest, if any, to, but excluding, the redemption date. In addition, if we undergo a fundamental change (as defined in the indenture governing the Convertible Notes), subject to certain conditions, holders may require us to repurchase for cash all or any portion of their Convertible Notes at a repurchase price equal to 100% of the principal amount of the Convertible Notes to be repurchased, plus accrued and unpaid special interest, if any, to, but excluding, the fundamental change repurchase date. In addition, following certain corporate events that occur prior to the maturity date of the Convertible Notes or if we deliver a notice of redemption in respect of some or all of the Convertible Notes, we will, in certain circumstances, increase the conversion rate of the Convertible Notes for a holder who elects to convert our Convertible Notes in connection with such a corporate event or convert our Convertible Notes called (or deemed called) for redemption during the related redemption period, as the case may be. Contemporaneously with the issuance of the Convertible Notes, Shake Shack Inc. entered into an intercompany note with SSE Holdings, LLC (“Intercompany Note”). SSE Holdings promises to pay Shake Shack, Inc., for value received, the principal amount with interest of the Intercompany Note in March 2028. Shake Shack Inc. will exercise its right to convert the Intercompany Note to maintain at all times a one-to-one ratio between the number of common units, directly or indirectly, by Shake Shack Inc and the aggregate number of outstanding shares of common stock. As of March 31, 2021, the Convertible Notes had a gross principal balance of $250,000 and a balance of $242,875, net of unamortized discount and debt issuance costs of $7,125. As of March 31, 2021, the unamortized balance of discount and debt issuance costs was recorded as a contra-liability and netted with Long-term debt on the Condensed Consolidated Balance Sheets and was being amortized as interest expense using the effective interest method. Total amortization expense was $86 for the thirteen weeks ended March 31, 2021 and was included in Interest expense in the Condensed Consolidated Statements of Income (Loss). In connection with the Convertible Notes, we also incurred costs of $236, including consulting and advisory fees, in the thirteen weeks ended March 31, 2021 and was included in General and administrative expense in the Condensed Consolidated Statements of Income (Loss). At March 31, 2021, the fair value of the Convertible Notes was approximately $248,125, based on external pricing data, including available quoted market prices of these instruments, and consideration of comparable debt instruments with similar interest rates and trading frequency, among other factors, and is classified as a Level 2 measurement within the fair value hierarchy.

LEASES

LEASES	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
LEASES	LEASES Nature of Leases We currently lease all of our domestic Company-operated Shacks, our home office and certain equipment under various non-cancelable lease agreements that expire on various dates through 2037. We evaluate contracts entered into to determine whether the contract involves the use of property or equipment, which is either explicitly or implicitly identified in the contract. We evaluate whether we control the use of the asset, which is determined by assessing whether we obtain substantially all economic benefits from the use of the asset, and whether we have the right to direct the use of the asset. If these criteria are met and we have identified a lease, we account for the contract under the requirements of Accounting Standards Codification Topic 842 ("ASC 842"). Upon the possession of a leased asset, we determine its classification as an operating or finance lease. Our real estate leases are classified as operating leases and most of our equipment leases are classified as finance leases. Generally, our real estate leases have initial terms ranging from 10 to 15 years and typically include two five-year renewal options. Renewal options are generally not recognized as part of the right-of-use assets and lease liabilities as it is not reasonably certain at commencement date that we would exercise the options to extend the lease. Our real estate leases typically provide for fixed minimum rent payments and/or contingent rent payments based upon sales in excess of specified thresholds. When the achievement of such sales thresholds are deemed to be probable, contingent rent is accrued in proportion to the sales recognized during the period. Fixed minimum rent payments are recognized on a straight-line basis over the lease term from the date we take possession of the leased property. Lease expense incurred before a Shack opens is recorded in Pre-opening costs on the Condensed Consolidated Statements of Income (Loss). Once a domestic Company-operated Shack opens, we record the straight-line lease expense and any contingent rent, if applicable, in Occupancy and related expenses on the Condensed Consolidated Statements of Income (Loss). Many of our leases also require us to pay real estate taxes, common area maintenance costs and other occupancy costs which are included in Occupancy and related expenses on the Condensed Consolidated Statements of Income (Loss). As there are no explicit rates provided in our leases, we use our incremental borrowing rate in determining the present value of future lease payments. The discount rate used to measure the lease liability is derived from the average of the yield curves obtained from using the notching method and the recovery rate method. The most significant assumption in calculating the incremental borrowing rate is our credit rating and is subject to judgment. We determined our credit rating based on a comparison of the financial information of SSE Holdings to other public companies and then used their respective credit ratings to develop our own. We expend cash for leasehold improvements to build out and equip our leased premises. Generally, a portion of the leasehold improvements and building costs are reimbursed by our landlords as landlord incentives pursuant to agreed-upon terms in our lease agreements. If obtained, landlord incentives usually take the form of cash, full or partial credits against our future minimum or contingent rents otherwise payable by us, or a combination thereof. In most cases, landlord incentives are received after we take possession of the property, as we meet required milestones during the construction of the property. We include these amounts in the measurement of the initial operating lease liability, which are also reflected as a reduction to the initial measurement of the right-of-use asset. A summary of finance and operating lease right-of-use assets and liabilities as of March 31, 2021 and December 30, 2020 is as follows: Classification March 31 December 30 Finance leases Property and equipment, net $ 6,315 $ 5,409 Operating leases Operating lease assets 312,087 306,317 Total right-of-use assets $ 318,402 $ 311,726 Finance leases: Other current liabilities $ 2,445 $ 1,998 Other long-term liabilities 4,056 3,586 Operating leases: Operating lease liabilities, current 37,275 35,657 Long-term operating lease liabilities 349,670 343,736 Total lease liabilities $ 393,446 $ 384,977 The components of lease expense for the thirteen weeks ended March 31, 2021 and March 25, 2020 was as follows: Thirteen Weeks Ended Classification March 31 March 25 Finance lease cost: Amortization of right-of-use assets Depreciation expense $ 613 $ 577 Interest on lease liabilities Interest expense 54 55 Operating lease cost Occupancy and related expenses 12,330 10,742 Short-term lease cost Occupancy and related expenses 82 124 Variable lease cost Occupancy and related expenses 2,851 3,730 Total lease cost $ 15,930 $ 15,228 As of March 31, 2021, future minimum lease payments for finance and operating leases consisted of the following: Finance Leases Operating Leases 2021 $ 2,023 $ 35,013 2022 2,183 53,111 2023 1,326 56,121 2024 689 55,896 2025 438 54,853 Thereafter 289 246,023 Total minimum payments 6,948 501,017 Less: imputed interest 447 114,072 Total lease liabilities $ 6,501 $ 386,945 As of March 31, 2021 we had additional operating lease commitments of $55,964 for non-cancelable leases without a possession date, which will begin to commence in 2021. These lease commitments are consistent with the leases that we have executed thus far. A summary of lease terms and discount rates for finance and operating leases as of March 31, 2021 and December 30, 2020 is as follows: March 31 December 30 Weighted-average remaining lease term (years): Finance leases 5.5 5.2 Operating leases 9.6 9.7 Weighted-average discount rate: Finance leases 3.5 % 3.6 % Operating leases 3.9 % 4.2 % Supplemental cash flow information related to leases for the thirteen weeks ended March 31, 2021 and March 25, 2020 is as follows: Thirteen Weeks Ended March 31 March 25 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases 54 $ 55 Operating cash flows from operating leases 11,825 11,329 Financing cash flows from finance leases 602 559 Right-of-use assets obtained in exchange for lease obligations: Finance leases 1,518 716 Operating leases 11,095 28,035
LEASES	LEASES Nature of Leases We currently lease all of our domestic Company-operated Shacks, our home office and certain equipment under various non-cancelable lease agreements that expire on various dates through 2037. We evaluate contracts entered into to determine whether the contract involves the use of property or equipment, which is either explicitly or implicitly identified in the contract. We evaluate whether we control the use of the asset, which is determined by assessing whether we obtain substantially all economic benefits from the use of the asset, and whether we have the right to direct the use of the asset. If these criteria are met and we have identified a lease, we account for the contract under the requirements of Accounting Standards Codification Topic 842 ("ASC 842"). Upon the possession of a leased asset, we determine its classification as an operating or finance lease. Our real estate leases are classified as operating leases and most of our equipment leases are classified as finance leases. Generally, our real estate leases have initial terms ranging from 10 to 15 years and typically include two five-year renewal options. Renewal options are generally not recognized as part of the right-of-use assets and lease liabilities as it is not reasonably certain at commencement date that we would exercise the options to extend the lease. Our real estate leases typically provide for fixed minimum rent payments and/or contingent rent payments based upon sales in excess of specified thresholds. When the achievement of such sales thresholds are deemed to be probable, contingent rent is accrued in proportion to the sales recognized during the period. Fixed minimum rent payments are recognized on a straight-line basis over the lease term from the date we take possession of the leased property. Lease expense incurred before a Shack opens is recorded in Pre-opening costs on the Condensed Consolidated Statements of Income (Loss). Once a domestic Company-operated Shack opens, we record the straight-line lease expense and any contingent rent, if applicable, in Occupancy and related expenses on the Condensed Consolidated Statements of Income (Loss). Many of our leases also require us to pay real estate taxes, common area maintenance costs and other occupancy costs which are included in Occupancy and related expenses on the Condensed Consolidated Statements of Income (Loss). As there are no explicit rates provided in our leases, we use our incremental borrowing rate in determining the present value of future lease payments. The discount rate used to measure the lease liability is derived from the average of the yield curves obtained from using the notching method and the recovery rate method. The most significant assumption in calculating the incremental borrowing rate is our credit rating and is subject to judgment. We determined our credit rating based on a comparison of the financial information of SSE Holdings to other public companies and then used their respective credit ratings to develop our own. We expend cash for leasehold improvements to build out and equip our leased premises. Generally, a portion of the leasehold improvements and building costs are reimbursed by our landlords as landlord incentives pursuant to agreed-upon terms in our lease agreements. If obtained, landlord incentives usually take the form of cash, full or partial credits against our future minimum or contingent rents otherwise payable by us, or a combination thereof. In most cases, landlord incentives are received after we take possession of the property, as we meet required milestones during the construction of the property. We include these amounts in the measurement of the initial operating lease liability, which are also reflected as a reduction to the initial measurement of the right-of-use asset. A summary of finance and operating lease right-of-use assets and liabilities as of March 31, 2021 and December 30, 2020 is as follows: Classification March 31 December 30 Finance leases Property and equipment, net $ 6,315 $ 5,409 Operating leases Operating lease assets 312,087 306,317 Total right-of-use assets $ 318,402 $ 311,726 Finance leases: Other current liabilities $ 2,445 $ 1,998 Other long-term liabilities 4,056 3,586 Operating leases: Operating lease liabilities, current 37,275 35,657 Long-term operating lease liabilities 349,670 343,736 Total lease liabilities $ 393,446 $ 384,977 The components of lease expense for the thirteen weeks ended March 31, 2021 and March 25, 2020 was as follows: Thirteen Weeks Ended Classification March 31 March 25 Finance lease cost: Amortization of right-of-use assets Depreciation expense $ 613 $ 577 Interest on lease liabilities Interest expense 54 55 Operating lease cost Occupancy and related expenses 12,330 10,742 Short-term lease cost Occupancy and related expenses 82 124 Variable lease cost Occupancy and related expenses 2,851 3,730 Total lease cost $ 15,930 $ 15,228 As of March 31, 2021, future minimum lease payments for finance and operating leases consisted of the following: Finance Leases Operating Leases 2021 $ 2,023 $ 35,013 2022 2,183 53,111 2023 1,326 56,121 2024 689 55,896 2025 438 54,853 Thereafter 289 246,023 Total minimum payments 6,948 501,017 Less: imputed interest 447 114,072 Total lease liabilities $ 6,501 $ 386,945 As of March 31, 2021 we had additional operating lease commitments of $55,964 for non-cancelable leases without a possession date, which will begin to commence in 2021. These lease commitments are consistent with the leases that we have executed thus far. A summary of lease terms and discount rates for finance and operating leases as of March 31, 2021 and December 30, 2020 is as follows: March 31 December 30 Weighted-average remaining lease term (years): Finance leases 5.5 5.2 Operating leases 9.6 9.7 Weighted-average discount rate: Finance leases 3.5 % 3.6 % Operating leases 3.9 % 4.2 % Supplemental cash flow information related to leases for the thirteen weeks ended March 31, 2021 and March 25, 2020 is as follows: Thirteen Weeks Ended March 31 March 25 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases 54 $ 55 Operating cash flows from operating leases 11,825 11,329 Financing cash flows from finance leases 602 559 Right-of-use assets obtained in exchange for lease obligations: Finance leases 1,518 716 Operating leases 11,095 28,035

NON-CONTROLLING INTERESTS

NON-CONTROLLING INTERESTS	3 Months Ended
	Mar. 31, 2021
Noncontrolling Interest [Abstract]
NON-CONTROLLING INTERESTS	NON-CONTROLLING INTERESTSWe are the sole managing member of SSE Holdings and, as a result, consolidate the financial results of SSE Holdings. We report a non-controlling interest representing the economic interest in SSE Holdings held by the other members of SSE Holdings. The Third Amended and Restated Limited Liability Company Agreement, as further amended, (the "LLC Agreement") of SSE Holdings provides that holders of LLC Interests may, from time to time, require SSE Holdings to redeem all or a portion of their LLC Interests for newly-issued shares of Class A common stock on a one-for-one basis. In connection with any redemption or exchange, we will receive a corresponding number of LLC Interests, increasing our total ownership interest in SSE Holdings. Changes in our ownership interest in SSE Holdings while we retain our controlling interest in SSE Holdings will be accounted for as equity transactions. As such, future redemptions or direct exchanges of LLC Interests in SSE Holdings by the other members of SSE Holdings will result in a change in ownership and reduce the amount recorded as non-controlling interest and increase additional paid-in capital. The following table summarizes the ownership interest in SSE Holdings as of March 31, 2021 and December 30, 2020. March 31, 2021 December 30, 2020 LLC Interests Ownership% LLC Interests Ownership % Number of LLC Interests held by Shake Shack Inc. 39,103,239 93.0 % 38,717,790 92.9 % Number of LLC Interests held by non-controlling interest holders 2,921,588 7.0 % 2,951,188 7.1 % Total LLC Interests outstanding 42,024,827 100.0 % 41,668,978 100.0 % The weighted average ownership percentages for the applicable reporting periods are used to attribute Net income (loss) and Other comprehensive income (loss) to Shake Shack Inc. and the non-controlling interest holders. The non-controlling interest holders' weighted average ownership percentage for the thirteen weeks ended March 31, 2021 and March 25, 2020 was 7.0% and 8.4%, respectively. The following table summarizes the effects of changes in ownership of SSE Holdings on our equity during the thirteen weeks ended March 31, 2021 and March 25, 2020. Thirteen Weeks Ended March 31 March 25 Net income (loss) attributable to Shake Shack Inc. $ 1,309 $ (960) Transfers (to) from non-controlling interests: Increase in additional paid-in capital as a result of the redemption of LLC Interests 36 195 Increase (decrease) in additional paid-in capital as a result of activity under stock compensation plans and the related income tax effect 3,359 424 Total effect of changes in ownership interest on equity attributable to Shake Shack Inc. $ 4,704 $ (341) The following table summarizes redemptions of LLC Interests activity during the thirteen weeks ended March 31, 2021 and March 25, 2020. Thirteen Weeks Ended March 31 March 25 Redemption and acquisition of LLC Interests Number of LLC Interests redeemed by non-controlling interest holders 29,600 28,195 Number of LLC Interests received by Shake Shack Inc. 29,600 28,195 Issuance of Class A common stock Shares of Class A common stock issued in connection with redemptions of LLC Interests 29,600 28,195 Cancellation of Class B common stock Shares of Class B common stock surrendered and canceled 29,600 28,195

EQUITY-BASED COMPENSATION

EQUITY-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
EQUITY-BASED COMPENSATION	EQUITY-BASED COMPENSATION A summary of equity-based compensation expense recognized during the thirteen weeks ended March 31, 2021 and March 25, 2020 is as follows: Thirteen Weeks Ended March 31 March 25 Stock options $ 20 $ 261 Performance stock units 414 413 Restricted stock units 1,247 626 Equity-based compensation expense $ 1,681 $ 1,300 Total income tax benefit recognized related to equity-based compensation $ 67 $ 36 Equity-based compensation expense is included in General and administrative expenses and Labor and related expenses on the Condensed Consolidated Statements of Income (Loss) during the thirteen weeks ended March 31, 2021 and March 25, 2020 as follows: Thirteen Weeks Ended March 31 March 25 General and administrative expenses $ 1,541 $ 1,214 Labor and related expenses 140 86 Equity-based compensation expense $ 1,681 $ 1,300

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES We are the sole managing member of SSE Holdings and, as a result, consolidate the financial results of SSE Holdings. SSE Holdings is treated as a partnership for U.S. federal and most applicable state and local income tax purposes. As a partnership, SSE Holdings is not subject to U.S. federal and certain state and local income taxes. Any taxable income or loss generated by SSE Holdings is passed through to and included in the taxable income or loss of its members, including us, on a pro rata basis. We are subject to U.S. federal income taxes, in addition to state and local income taxes with respect to our allocable share of any taxable income or loss of SSE Holdings, as well as any stand-alone income or loss generated by Shake Shack Inc. We are also subject to withholding taxes in foreign jurisdictions. Our effective income tax rates for the thirteen weeks ended March 31, 2021 and March 25, 2020 were 105.5% and (8.8)%, respectively. The increase was primarily driven by lower pre-tax book income resulting in a loss, causing tax credits and windfall tax benefits related to equity-based compensation to have an increasing effect on the tax rate, as well as a reduction of a valuation allowance. Additionally, an increase in our ownership interest in SSE Holdings increases our share of the taxable income (loss) of SSE Holdings. Our weighted-average ownership interest in SSE Holdings was 93.0% and 91.6% for the thirteen weeks ended March 31, 2021 and March 25, 2020, respectively. Deferred Tax Assets and Liabilities During the thirteen weeks ended March 31, 2021, we acquired an aggregate of 385,449 LLC Interests in connection with the redemption of LLC Interests, and activity relating to our stock compensation plan. We recognized a deferred tax asset in the amount of $10,204 associated with the basis difference in our investment in SSE Holdings upon acquisition of these LLC Interests. As of March 31, 2021, the total deferred tax asset related to the basis difference in our investment in SSE Holdings was $142,867. However, a portion of the total basis difference will only reverse upon the eventual sale of our interest in SSE Holdings, which we expect would result in a capital loss. As of March 31, 2021, the total valuation allowance established against the deferred tax asset to which this portion relates was $1,260. During the thirteen weeks ended March 31, 2021, we also recognized $300 of deferred tax assets related to additional tax basis increases generated from expected future payments under the Tax Receivable Agreement and related deductions for imputed interest on such payments. See "Tax Receivable Agreement," herein for more information. We evaluate the realizability of our deferred tax assets on a quarterly basis and establish valuation allowances when it is more likely than not that all or a portion of a deferred tax asset may not be realized. As of March 31, 2021, we concluded, based on the weight of all available positive and negative evidence, that all of our deferred tax assets (except for those deferred tax assets described above relating to basis differences that are expected to result in a capital loss upon eventual sale of our interest in SSE Holdings, New York City UBT credits and certain foreign tax credits) are more likely than not to be realized. As such, no additional valuation allowance was recognized. Tax Receivable Agreement Pursuant to our election under Section 754 of the Internal Revenue Code (the "Code"), we expect to obtain an increase in our share of the tax basis in the net assets of SSE Holdings when LLC Interests are redeemed or exchanged by the other members of SSE Holdings. We plan to make an election under Section 754 of the Code for each taxable year in which a redemption or exchange of LLC Interest occurs. We intend to treat any redemptions and exchanges of LLC Interests as direct purchases of LLC Interests for U.S. federal income tax purposes. These increases in tax basis may reduce the amounts that we would otherwise pay in the future to various tax authorities. They may also decrease gains (or increase losses) on future dispositions of certain capital assets to the extent tax basis is allocated to those capital assets. On February 4, 2015, we entered into a tax receivable agreement with certain of the then-existing members of SSE Holdings (the "Tax Receivable Agreement") that provides for the payment by us of 85% of the amount of any tax benefits that we actually realize, or in some cases are deemed to realize, as a result of (i) increases in our share of the tax basis in the net assets of SSE Holdings resulting from any redemptions or exchanges of LLC Interests, (ii) tax basis increases attributable to payments made under the Tax Receivable Agreement, and (iii) deductions attributable to imputed interest pursuant to the Tax Receivable Agreement (the "TRA Payments"). We expect to benefit from the remaining 15% of any tax benefits that we may actually realize. The TRA Payments are not conditioned upon any continued ownership interest in SSE Holdings or us. The rights of each member of SSE Holdings that is a party to the Tax Receivable Agreement, are assignable to transferees of their respective LLC Interests. During the thirteen weeks ended March 31, 2021, we acquired an aggregate of 29,600 LLC Interests in connection with the redemption of LLC Interests, which resulted in an increase in the tax basis of our investment in SSE Holdings subject to the provisions of the Tax Receivable Agreement. We recognized an additional liability in the amount of $1,094 for the TRA Payments due to the redeeming members, representing 85% of the aggregate tax benefits we expect to realize from the tax basis increases related to the redemption of LLC Interests, after concluding it was probable that such TRA Payments would be paid based on our estimates of future taxable income. During the thirteen weeks ended March 31, 2021 and March 25, 2020, payments of $0 and $6,569, inclusive of interest, were made to the parties to the Tax Receivable Agreement, respectively. As of March 31, 2021, the total amount of TRA Payments due under the Tax Receivable Agreement, was $234,048. See Note 13, Commitments and Contingencies, for more information relating to our liabilities under the Tax Receivable Agreement.

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS (LOSS) PER SHAREThe following table sets forth reconciliations of the numerators and denominators used to compute basic and diluted earnings (loss) per share of Class A common stock (in thousands, except per share amounts) for the thirteen weeks ended March 31, 2021 and March 25, 2020. Thirteen Weeks Ended March 31 March 25 Numerator: Net income (loss) attributable to Shake Shack Inc.—basic $ 1,309 $ (960) Reallocation of net loss attributable to non-controlling interests from the assumed conversion of Class B shares (734) — Net income (loss) attributable to Shake Shack Inc.—diluted $ 575 $ (960) Denominator: Weighted-average shares of Class A common stock outstanding—basic 38,948 34,444 Effect of dilutive securities: Stock options 232 — Performance stock units 53 — Restricted stock units 164 — Convertible Notes 451 — Shares of Class B common stock 2,941 — Weighted-average shares of Class A common stock outstanding—diluted 42,789 34,444 Earnings (loss) per share of Class A common stock—basic $ 0.03 $ (0.03) Earnings (loss) per share of Class A common stock—diluted $ 0.01 $ (0.03) Shares of our Class B common stock do not share in the earnings or losses of Shake Shack and are therefore not participating securities. As such, separate presentation of basic and diluted earnings (loss) per share of Class B common stock under the two-class method has not been presented. However, shares of our Class B common stock outstanding for the period are considered potentially dilutive shares of Class A common stock under application of the if-converted method and are included in the computation of diluted earnings (loss) per share, except when the effect would be antidilutive. The following table presents potentially dilutive securities, as of the end of the period, excluded from the computations of diluted earnings (loss) per share of Class A common stock for the thirteen weeks ended March 31, 2021 and March 25, 2020. Thirteen Weeks Ended March 31 March 25 Stock options 1,698 (1) 847,207 (3) Performance stock units 51,974 (2) 179,253 (3) Restricted stock units — 264,431 (3) Shares of Class B common stock — 3,117,002 (3) (1) Number of securities outstanding at the end of the period that were excluded from the computation of diluted earnings (loss) per share of Class A common stock because the exercise price of the stock options exceeded the average market price of our Class A common stock during the period ("out-of-the-money"). (2) Number of securities outstanding at the end of the period that were excluded from the computation of diluted earnings (loss) per share of Class A common stock because the performance conditions associated with these awards were not met assuming the end of the reporting period was the end of the performance period. (3) Number of securities outstanding at the end of the period that were excluded from the computation of diluted earnings (loss) per share of Class A common stock because the effect would have been anti-dilutive.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Lease Commitments We are obligated under various operating leases for Shacks and our home office space, expiring in various years through 2037. Under certain of these leases, we are liable for contingent rent based on a percentage of sales in excess of specified thresholds and are typically responsible for our proportionate share of real estate taxes, common area maintenance costs and other occupancy costs. See Note 7, Leases. As security under the terms of one of our leases, we are obligated under a letter of credit totaling $130 as of March 31, 2021, which expires in February 2026. Additionally, in September 2017, we entered into a letter of credit in conjunction with our new home office lease in the amount of $603, which expires in August 2021 and renews automatically for one-year periods through January 31, 2034. Purchase Commitments Purchase obligations include legally binding contracts, including commitments for the purchase, construction or remodeling of real estate and facilities, firm minimum commitments for inventory purchases, equipment purchases, marketing-related contracts, software acquisition/license commitments and service contracts. These obligations are generally short-term in nature and are recorded as liabilities when the related goods are received or services rendered. We also enter into long-term, exclusive contracts with certain vendors to supply us with food, beverages and paper goods, obligating us to purchase specified quantities. Legal Contingencies In March 2020, a claim was filed against Shake Shack alleging certain violations of the Fair Labor Standards Act. At a mediation between the parties, we agreed to settle the matter with the plaintiff and other employees who elect to participate in the settlement for $595. As of March 31, 2021, an accrual in the amount of $595 was recorded for this matter and related expenses. In February 2018, a claim was filed against Shake Shack in California state court alleging certain violations of the California Labor Code. At a mediation between the parties, we agreed to settle the matter with the plaintiff and all other California employees who elect to participate in the settlement for $1,200. As of March 31, 2021, an accrual in the amount of $1,180 was recorded for this matter and related expenses. We are subject to various legal proceedings, claims and liabilities, such as employment-related claims and slip and fall cases, which arise in the ordinary course of business and are generally covered by insurance. As of March 31, 2021, the amount of the ultimate liability with respect to these matters was not material. Liabilities under Tax Receivable Agreement

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS Union Square Hospitality Group The Chairman of our Board of Directors serves as the Chief Executive Officer of Union Square Hospitality Group, LLC. As a result, Union Square Hospitality Group, LLC and its subsidiaries, set forth below, are considered related parties. Hudson Yards Sports and Entertainment In fiscal 2011, we entered into a Master License Agreement (as amended, "MLA") with Hudson Yards Sports and Entertainment LLC ("HYSE") to operate Shake Shack branded limited menu concession stands in sports and entertainment venues within the United States. In February 2019, the agreement was assigned to Hudson Yards Catering ("HYC"), the parent of HYSE. The agreement expires in January 2027 and includes five consecutive five-year renewal options at HYC's option. As consideration for these rights, HYC pays us a license fee based on a percentage of net food sales, as defined in the MLA. HYC also pays us a percentage of profits on sales of branded beverages, as defined in the MLA. Thirteen Weeks Ended Classification March 31 March 25 Amounts received from HYC Licensing revenue $ — $ 22 Classification March 31 December 30 Amounts due from HYC Accounts Receivable $ — $ 8 Madison Square Park Conservancy The Chairman of our Board of Directors serves as a director of the Madison Square Park Conservancy ("MSP Conservancy"), with which we have a license agreement and pay license fees to operate our Madison Square Park Shack. No amounts were due to MSP Conservancy as of both March 31, 2021 and December 30, 2020. Thirteen Weeks Ended Classification March 31 March 25 Amounts paid to MSP Conservancy Occupancy and related expenses $ 215 $ 219 Olo, Inc. The Chairman of our Board of Directors serves as a director of Olo, Inc. (formerly known as "Mobo Systems, Inc."), a platform we use in connection with our mobile ordering application. No amounts were due to Olo as of both March 31, 2021 and December 30, 2020. Thirteen Weeks Ended Classification March 31 March 25 Amounts paid to Olo Other operating expenses $ 147 $ 52 Square, Inc. Our Chief Executive Officer is a member of the Board of Directors of Square, Inc. ("Square"). We currently use certain point-of-sale applications, payment processing services, hardware and other enterprise platform services in connection with the processing of a limited amount of sales at certain of our locations, sales for certain off-site events and in connection with our kiosk technology. Thirteen Weeks Ended Classification March 31 March 25 Amounts paid to Square Other operating expenses $ 462 $ 571 Thirteen Weeks Ended Classification March 31 March 25 Amounts due to Square Accounts Payable $ 9 $ — USHG Acquisition Corp. Our Chief Executive Officer has been appointed to the board of directors of USHG Acquisition Corp. in which the Chairman of our Board of Directors serves as the chairman of the board of directors of USHG Acquisition Corp. USHG Acquisition Corp. is a newly organized blank check company incorporated for the purpose of effecting a merger, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses or entities. No amounts were due to or due from USHG Acquisition Corp as of both March 31, 2021 and December 30, 2020. Tax Receivable Agreement As described in Note 10, Income Taxes, we entered into a Tax Receivable Agreement with certain members of SSE Holdings that provides for the payment by us of 85% of the amount of tax benefits, if any, that Shake Shack actually realizes or in some cases is deemed to realize as a result of certain transactions. Thirteen Weeks Ended Classification March 31 March 25 Amounts paid to members (inclusive of interest) Other current liabilities $ — $ 6,569 Classification March 31 December 30 Amounts due under the Tax Receivable Agreement Other current liabilities $ 234,048 $ 232,954 Distributions to Members of SSE Holdings Under the terms of the SSE Holdings LLC Agreement, SSE Holdings is obligated to make tax distributions to its members. No tax distributions were payable to non-controlling interest holders as of March 31, 2021 and December 30, 2020, respectively. Thirteen Weeks Ended Classification March 31 March 25 Amounts paid to non-controlling interest holders Non-controlling interests $ 467 $ 305

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of Shake Shack Inc. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. These interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") and on a basis consistent in all material respects with the accounting policies described in our Annual Report on Form 10-K for the fiscal year ended December 30, 2020 ("2020 Form 10-K"). Certain information and footnote disclosures normally presented in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes thereto included in our 2020 Form 10-K. In our opinion, all adjustments, which are normal and recurring in nature, necessary for a fair presentation of our financial position and results of operation have been included. Operating results for interim periods are not necessarily indicative of the results that may be expected for a full fiscal year. SSE Holdings is considered a variable interest entity. Shake Shack Inc. is the primary beneficiary as we have the majority economic interest in SSE Holdings and, as the sole managing member, have decision making authority that significantly affects the economic performance of the entity, while the limited partners have no substantive kick-out or participating rights. As a result, we consolidate SSE Holdings. The assets and liabilities of SSE Holdings represent substantially all of our consolidated assets and liabilities with the exception of certain deferred taxes and liabilities under the Tax Receivable Agreement. As of March 31, 2021 and December 30, 2020, the net assets of SSE Holdings were $380,713 and $383,669, respectively. The assets of SSE Holdings are subject to certain restrictions in SSE Holdings' revolving credit agreement. See Note 6, Debt, for more information.
Fiscal Year	Fiscal Year We operate on a 52/53 week fiscal year ending on the last Wednesday in December. Fiscal 2021 contains 52 weeks and ends on December 29, 2021. Fiscal 2020 contained 53 weeks and ended on December 30, 2020. Unless otherwise stated, references to years in this report relate to fiscal years.
Use of Estimates	Use of Estimates The preparation of these condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and
Recently Adopted and Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements We adopted the Accounting Standards Updates (“ASUs”) summarized below in fiscal 2021. Accounting Standards Update Description Date Simplifying the Accounting for Income Taxes (ASU 2019-12) This standard simplifies various aspects related to accounting for income taxes by removing certain exceptions to the general principles in ASC 740, “Income Taxes” (“ASC 740”), and clarifying certain aspects of the current guidance to promote consistency among reporting entities. The adoption of this standard did not have a material impact to our condensed consolidated financial statements. December 31, 2020 Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity's Own (ASU 2020-06) This ASU amends the guidance on convertible instruments and the derivatives scope exception for contracts in an entity’s own equity and improves and amends the related earnings per share guidance for both Subtopics. We elected to early adopt this standard, beginning December 31, 2020. The guidance of this ASU is applicable to our convertible notes issued in March 2021. As a result, the convertible notes are accounted for as a single liability measured at amortized cost. The if-converted earnings per share ("EPS") method is used, with the effect of potential share settlement included in diluted EPS. Refer to Note 6, Debt, for further details of the convertible notes issued. December 31, 2020

REVENUE (Tables)

REVENUE (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	Revenue recognized during the thirteen weeks ended March 31, 2021 and March 25, 2020, disaggregated by type is as follows: Thirteen Weeks Ended March 31 March 25 Shack sales $ 150,668 $ 138,048 Licensing revenue: Sales-based royalties 4,425 4,944 Initial territory and opening fees 189 178 Total revenue $ 155,282 $ 143,170
Schedule of Contract with Customer, Asset and Liability	Opening and closing balances of contract liabilities and receivables from contracts with customers is as follows: March 31 December 31 Shack sales receivables $ 5,641 $ 5,373 Licensing receivables, net of allowance for doubtful accounts 2,420 2,647 Gift card liability 2,600 2,637 Deferred revenue, current 612 608 Deferred revenue, long-term 11,965 12,151 Revenue recognized during the thirteen weeks ended March 31, 2021 and March 25, 2020 that was included in their respective liability balances at the beginning of the period is as follows: Thirteen Weeks Ended March 31 March 25 Gift card liability $ 219 $ 300 Deferred revenue 181 175

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Assets Measured On A Recurring Basis	Our assets measured at fair value on a recurring basis as of March 31, 2021 and December 30, 2020 were as follows: Fair Value Measurements March 31 December 30 Level 1 Level 1 Equity securities: Mutual funds $ 40,914 $ 36,887 Total Marketable securities $ 40,914 $ 36,887

SUPPLEMENTAL BALANCE SHEET IN_2

SUPPLEMENTAL BALANCE SHEET INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2021
Supplemental Balance Sheet Disclosures [Abstract]
Supplemental Balance Sheet Information	The components of Other current liabilities as of March 31, 2021 and December 30, 2020 are as follows: March 31 December 30 Sales tax payable $ 4,045 $ 4,285 Gift card liability 2,600 2,637 Current portion of financing equipment lease liabilities 2,445 1,998 Other 5,997 5,280 Other current liabilities $ 15,087 $ 14,200 The components of Other long-term liabilities as of March 31, 2021 and December 30, 2020 are as follows: March 31 December 30 Deferred licensing revenue $ 11,965 $ 12,151 Long-term portion of financing equipment lease liabilities 4,056 3,586 Other (1) 6,276 8,723 Other long-term liabilities $ 22,297 $ 24,460 (1) As of March 31, 2021, Other included $3,359 of deferred lease incentive liabilities related to leases with variable lease cost as well as $2,607 of deferred Social Security taxes associated with the Coronavirus Aid, Relief, and Economic Security Act.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Lease, Cost	A summary of finance and operating lease right-of-use assets and liabilities as of March 31, 2021 and December 30, 2020 is as follows: Classification March 31 December 30 Finance leases Property and equipment, net $ 6,315 $ 5,409 Operating leases Operating lease assets 312,087 306,317 Total right-of-use assets $ 318,402 $ 311,726 Finance leases: Other current liabilities $ 2,445 $ 1,998 Other long-term liabilities 4,056 3,586 Operating leases: Operating lease liabilities, current 37,275 35,657 Long-term operating lease liabilities 349,670 343,736 Total lease liabilities $ 393,446 $ 384,977 The components of lease expense for the thirteen weeks ended March 31, 2021 and March 25, 2020 was as follows: Thirteen Weeks Ended Classification March 31 March 25 Finance lease cost: Amortization of right-of-use assets Depreciation expense $ 613 $ 577 Interest on lease liabilities Interest expense 54 55 Operating lease cost Occupancy and related expenses 12,330 10,742 Short-term lease cost Occupancy and related expenses 82 124 Variable lease cost Occupancy and related expenses 2,851 3,730 Total lease cost $ 15,930 $ 15,228 A summary of lease terms and discount rates for finance and operating leases as of March 31, 2021 and December 30, 2020 is as follows: March 31 December 30 Weighted-average remaining lease term (years): Finance leases 5.5 5.2 Operating leases 9.6 9.7 Weighted-average discount rate: Finance leases 3.5 % 3.6 % Operating leases 3.9 % 4.2 % Supplemental cash flow information related to leases for the thirteen weeks ended March 31, 2021 and March 25, 2020 is as follows: Thirteen Weeks Ended March 31 March 25 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases 54 $ 55 Operating cash flows from operating leases 11,825 11,329 Financing cash flows from finance leases 602 559 Right-of-use assets obtained in exchange for lease obligations: Finance leases 1,518 716 Operating leases 11,095 28,035
Lessee, Operating Lease, Liability, Maturity	As of March 31, 2021, future minimum lease payments for finance and operating leases consisted of the following: Finance Leases Operating Leases 2021 $ 2,023 $ 35,013 2022 2,183 53,111 2023 1,326 56,121 2024 689 55,896 2025 438 54,853 Thereafter 289 246,023 Total minimum payments 6,948 501,017 Less: imputed interest 447 114,072 Total lease liabilities $ 6,501 $ 386,945
Finance Lease, Liability, Maturity	As of March 31, 2021, future minimum lease payments for finance and operating leases consisted of the following: Finance Leases Operating Leases 2021 $ 2,023 $ 35,013 2022 2,183 53,111 2023 1,326 56,121 2024 689 55,896 2025 438 54,853 Thereafter 289 246,023 Total minimum payments 6,948 501,017 Less: imputed interest 447 114,072 Total lease liabilities $ 6,501 $ 386,945

NON-CONTROLLING INTERESTS (Tabl

NON-CONTROLLING INTERESTS (Tables)	3 Months Ended
	Mar. 31, 2021
Noncontrolling Interest [Abstract]
Schedule of Ownership Interests in SSE Holdings	The following table summarizes the ownership interest in SSE Holdings as of March 31, 2021 and December 30, 2020. March 31, 2021 December 30, 2020 LLC Interests Ownership% LLC Interests Ownership % Number of LLC Interests held by Shake Shack Inc. 39,103,239 93.0 % 38,717,790 92.9 % Number of LLC Interests held by non-controlling interest holders 2,921,588 7.0 % 2,951,188 7.1 % Total LLC Interests outstanding 42,024,827 100.0 % 41,668,978 100.0 %
Schedule of Non-Controlling Interest	The following table summarizes the effects of changes in ownership of SSE Holdings on our equity during the thirteen weeks ended March 31, 2021 and March 25, 2020. Thirteen Weeks Ended March 31 March 25 Net income (loss) attributable to Shake Shack Inc. $ 1,309 $ (960) Transfers (to) from non-controlling interests: Increase in additional paid-in capital as a result of the redemption of LLC Interests 36 195 Increase (decrease) in additional paid-in capital as a result of activity under stock compensation plans and the related income tax effect 3,359 424 Total effect of changes in ownership interest on equity attributable to Shake Shack Inc. $ 4,704 $ (341)
Redemption of LLC Interests	The following table summarizes redemptions of LLC Interests activity during the thirteen weeks ended March 31, 2021 and March 25, 2020. Thirteen Weeks Ended March 31 March 25 Redemption and acquisition of LLC Interests Number of LLC Interests redeemed by non-controlling interest holders 29,600 28,195 Number of LLC Interests received by Shake Shack Inc. 29,600 28,195 Issuance of Class A common stock Shares of Class A common stock issued in connection with redemptions of LLC Interests 29,600 28,195 Cancellation of Class B common stock Shares of Class B common stock surrendered and canceled 29,600 28,195

EQUITY-BASED COMPENSATION (Tabl

EQUITY-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Equity-Based Compensation Expense Recognized	A summary of equity-based compensation expense recognized during the thirteen weeks ended March 31, 2021 and March 25, 2020 is as follows: Thirteen Weeks Ended March 31 March 25 Stock options $ 20 $ 261 Performance stock units 414 413 Restricted stock units 1,247 626 Equity-based compensation expense $ 1,681 $ 1,300 Total income tax benefit recognized related to equity-based compensation $ 67 $ 36 Equity-based compensation expense is included in General and administrative expenses and Labor and related expenses on the Condensed Consolidated Statements of Income (Loss) during the thirteen weeks ended March 31, 2021 and March 25, 2020 as follows: Thirteen Weeks Ended March 31 March 25 General and administrative expenses $ 1,541 $ 1,214 Labor and related expenses 140 86 Equity-based compensation expense $ 1,681 $ 1,300

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Schedule of Earnings Per Share	The following table sets forth reconciliations of the numerators and denominators used to compute basic and diluted earnings (loss) per share of Class A common stock (in thousands, except per share amounts) for the thirteen weeks ended March 31, 2021 and March 25, 2020. Thirteen Weeks Ended March 31 March 25 Numerator: Net income (loss) attributable to Shake Shack Inc.—basic $ 1,309 $ (960) Reallocation of net loss attributable to non-controlling interests from the assumed conversion of Class B shares (734) — Net income (loss) attributable to Shake Shack Inc.—diluted $ 575 $ (960) Denominator: Weighted-average shares of Class A common stock outstanding—basic 38,948 34,444 Effect of dilutive securities: Stock options 232 — Performance stock units 53 — Restricted stock units 164 — Convertible Notes 451 — Shares of Class B common stock 2,941 — Weighted-average shares of Class A common stock outstanding—diluted 42,789 34,444 Earnings (loss) per share of Class A common stock—basic $ 0.03 $ (0.03) Earnings (loss) per share of Class A common stock—diluted $ 0.01 $ (0.03) The following table presents potentially dilutive securities, as of the end of the period, excluded from the computations of diluted earnings (loss) per share of Class A common stock for the thirteen weeks ended March 31, 2021 and March 25, 2020. Thirteen Weeks Ended March 31 March 25 Stock options 1,698 (1) 847,207 (3) Performance stock units 51,974 (2) 179,253 (3) Restricted stock units — 264,431 (3) Shares of Class B common stock — 3,117,002 (3) (1) Number of securities outstanding at the end of the period that were excluded from the computation of diluted earnings (loss) per share of Class A common stock because the exercise price of the stock options exceeded the average market price of our Class A common stock during the period ("out-of-the-money"). (2) Number of securities outstanding at the end of the period that were excluded from the computation of diluted earnings (loss) per share of Class A common stock because the performance conditions associated with these awards were not met assuming the end of the reporting period was the end of the performance period. (3) Number of securities outstanding at the end of the period that were excluded from the computation of diluted earnings (loss) per share of Class A common stock because the effect would have been anti-dilutive.

NATURE OF OPERATIONS (Details)

NATURE OF OPERATIONS (Details)	Mar. 31, 2021RestaurantShack
Class of Stock [Line Items]
Number of restaurants	321
United States | Company-operated
Class of Stock [Line Items]
Number of restaurants	192
United States | Licensed
Class of Stock [Line Items]
Number of restaurants	22
Number of Shacks closed | Shack	16
Non-United States | Licensed
Class of Stock [Line Items]
Number of restaurants	107

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 30, 2020
Variable Interest Entity [Line Items]
Net assets held by SSE holders	$ 1,407,589	$ 1,145,348
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Net assets held by SSE holders	$ 380,713	$ 383,669

REVENUE - Narrative (Details)

REVENUE - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 30, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other long-term liabilities	$ 22,297	$ 24,460
Other current liabilities	15,087	$ 14,200
Revenue, remaining performance obligation	$ 16,748

REVENUE - Schedule of Revenue R

REVENUE - Schedule of Revenue Recognized (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 155,282	$ 143,170

REVENUE - Schedule of Disaggreg

REVENUE - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 155,282	$ 143,170
Shack Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	150,668	138,048
Sales-Based Royalties [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	4,425	4,944
Initial territory and opening fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 189	$ 178

REVENUE - Schedule of Respectiv

REVENUE - Schedule of Respective Liability Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 30, 2020
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Gift card liability	$ 2,600	$ 2,637
Deferred revenue, current	612	608
Deferred revenue, long-term	11,965	12,151
Shack Sales [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract with customer, asset, net	5,641	5,373
Licensing receivables, net of allowance for doubtful accounts
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract with customer, asset, net	$ 2,420	$ 2,647

REVENUE - Liability Balance (De

REVENUE - Liability Balance (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Revenue from Contract with Customer [Abstract]
Gift card liability	$ 219	$ 300
Deferred revenue	$ 181	$ 175

FAIR VALUE MEASUREMENTS - Asset

FAIR VALUE MEASUREMENTS - Assets Measured On a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 30, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	$ 40,914	$ 36,887
Level 1 | Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	$ 40,914	$ 36,887

FAIR VALUE MEASUREMENTS - Addit

FAIR VALUE MEASUREMENTS - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized Gain (Loss) on Securities	$ (46,000)	$ (356,000)
Asset impairment charges		1,132,000
Property, Plant and Equipment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges		736
Operating Lease, Right-of-Use Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges		383
Finance Lease, Right-of-Use Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges		$ 13

FAIR VALUE MEASUREMENTS - Other

FAIR VALUE MEASUREMENTS - Other Income From Available For Sale Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Available-for-sale securities
Unrealized Gain (Loss) on Securities	$ (46)	$ (356)
Total	31	(93)
Available-for-sale Securities
Available-for-sale securities
Dividend income	74	184
Realized gain (loss) on sale of investments	0	79
Unrealized Gain (Loss) on Securities	(46)	(356)
Total	$ 28	$ (93)

SUPPLEMENTAL BALANCE SHEET IN_3

SUPPLEMENTAL BALANCE SHEET INFORMATION (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 30, 2020
Supplemental Balance Sheet Disclosures [Abstract]
Finance Lease, Liability, Current	$ 2,445	$ 1,998
Other Liabilities, Current
Sales tax payable	4,045	4,285
Gift card liability	2,600	2,637
Other	5,997	5,280
Other current liabilities	$ 15,087	$ 14,200

SUPPLEMENTAL BALANCE SHEET IN_4

SUPPLEMENTAL BALANCE SHEET INFORMATION Other long-term liabilities (Details) - USD ($)	Mar. 31, 2021	Dec. 30, 2020	Sep. 23, 2020
Other Liabilities Disclosure [Abstract]
Contract with Customer, Liability, Noncurrent	$ 11,965,000	$ 12,151,000
Finance Lease, Liability, Noncurrent	4,056,000	3,586,000
Other Sundry Liabilities, Noncurrent	6,276,000	8,723,000
Other Liabilities, Noncurrent	$ 22,297,000	$ 24,460,000
Deferred lease incentive liabilities			$ 3,359
Deferred social security taxes			$ 2,607

DEBT (Details)

DEBT (Details) - USD ($)	Feb. 04, 2015	Mar. 31, 2021	May 31, 2020	Mar. 31, 2020	Mar. 31, 2021	Mar. 25, 2020	Dec. 30, 2020
Debt Instrument [Line Items]
Proceeds from revolving credit facility					$ 0	$ 50,000,000
Notes payable		$ 242,875,000			242,875,000		$ 0
Interest costs incurred					368,000	52,000
Payments of Financing Costs					$ 70,000	$ 0
0% Convertible Senior Notes | Private Placement
Debt Instrument [Line Items]
Conversion rate		5,867.9000
Class A Common Stock
Debt Instrument [Line Items]
Common stock par value (in dollars per share)		$ 0.001			$ 0.001		$ 0.001
Revolving Credit Facility
Debt Instrument [Line Items]
Payments of Financing Costs					$ 110,000
Notes payable
Debt Instrument [Line Items]
Proceeds from revolving credit facility				$ 50,000,000
Notes payable		$ 50,000,000			50,000,000
Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		50,000,000			50,000,000
Line of Credit Facility, Incremental Borrowing Capacity		100,000,000			100,000,000
Third Amendment and Restated Credit Arrangement | Line of credit
Debt Instrument [Line Items]
Term to maturity	5 years
Third Amendment and Restated Credit Arrangement | Letter of credit | Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 15,000,000			$ 15,000,000
First Amendment to the Credit Agreement | Line of credit
Debt Instrument [Line Items]
Debt instrument, minimum required liquidity			$ 25,000,000
First Amendment to the Credit Agreement | Minimum | Line of credit | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.00%
First Amendment to the Credit Agreement | Minimum | Line of credit | Prime rate
Debt Instrument [Line Items]
Basis spread on variable rate			0.00%
First Amendment to the Credit Agreement | Maximum | Line of credit | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			2.50%
First Amendment to the Credit Agreement | Maximum | Line of credit | Prime rate
Debt Instrument [Line Items]
Basis spread on variable rate			1.50%

DEBT - Convertible Notes (Detai

DEBT - Convertible Notes (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2021	Mar. 25, 2020	Dec. 30, 2020
Debt Instrument [Line Items]
Amortization of debt issuance costs		$ 86	$ 0
0% Convertible Senior Notes
Debt Instrument [Line Items]
Issuance of Class A common stock sold in equity offerings, net of underwriting discounts, commissions and offering costs	$ 225,000
0% Convertible Senior Notes | Private Placement
Debt Instrument [Line Items]
Issuance of Class A common stock sold in equity offerings, net of underwriting discounts, commissions and offering costs	$ 250,000
Conversion rate	5,867.9000
Conversion of stock, price per share	$ 170,420
Stock Issued During Period, Value, Net Of Debt Issuance Costs	$ 242,875
Debt issuance costs	7,125
Amortization of debt issuance costs	86
Payment of Financing and Stock Issuance Costs	236
0% Convertible Senior Notes | Private Placement | Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Equity, Fair Value Disclosure	248,125	$ 248,125
0% Convertible Senior Notes | Over-Allotment Option
Debt Instrument [Line Items]
Issuance of Class A common stock sold in equity offerings, net of underwriting discounts, commissions and offering costs	$ 25,000
Class A Common Stock
Debt Instrument [Line Items]
Common stock par value (in dollars per share)	$ 0.001	$ 0.001		$ 0.001

Leases Schedule of Accounting P

Leases Schedule of Accounting Pronouncements (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 30, 2020	Mar. 25, 2020
Leases [Abstract]
Prepaid Expense and Other Assets, Current	$ 7,805	$ 7,074
Property and equipment, net	(348,580)	(336,541)
Operating lease assets	312,087	306,317	$ 306,317
Long-term operating lease liabilities	349,670	343,736	$ 343,736
Other long-term liabilities	22,297	24,460
Retained earnings	13,518	12,209
Non-controlling interests	$ 26,017	$ 27,172

Lease Narrative (Details)

Lease Narrative (Details)	3 Months Ended
	Mar. 31, 2021option
Operating Leased Assets [Line Items]
Number of renewal options	2
Renewal term	5 years
Minimum
Operating Leased Assets [Line Items]
Term of contract	10 years
Maximum
Operating Leased Assets [Line Items]
Term of contract	15 years

Lease Cost (Details)

Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020	Dec. 30, 2020
Leases [Abstract]
Finance leases	$ 6,315	$ 5,409
Operating leases	312,087	306,317	$ 306,317
Total right-of-use assets	318,402	311,726
Other current liabilities, finance leases	2,445	1,998
Other long-term liabilities, finance leases	4,056	3,586
Operating lease liabilities, current	37,275	35,657	35,657
Long-term operating lease liabilities	349,670	343,736	$ 343,736
Finance leases	6,501
Operating leases	386,945
Total lease liabilities	393,446	384,977
Finance lease cost:
Amortization of right-of-use assets	613	577
Interest on lease liabilities	54	55
Operating lease cost	12,330	10,742
Short-term lease cost	82	124
Variable lease cost	2,851	3,730
Total lease cost	$ 15,930	15,228
Weighted Average Lease Term [Abstract]
Finance leases	5 years 6 months		5 years 2 months 12 days
Operating leases	9 years 7 months 6 days		9 years 8 months 12 days
Weighted Average Discount Rate [Abstract]
Finance leases	3.50%		3.60%
Operating leases	3.90%		4.20%
Operating cash flows from finance leases	$ 54	55
Operating cash flows from operating leases	11,825	11,329
Financing cash flows from finance leases	602	559
Finance leases	1,518	716
Operating leases	$ 11,095	$ 28,035

Lease Maturity (Details)

Lease Maturity (Details) $ in Thousands	Mar. 31, 2021USD ($)
Leases [Abstract]
Operating lease for non-cancellable leases	$ 55,964
Finance Lease, Liability, Payment, Due [Abstract]
2022	2,183
2023	1,326
2024	689
2025	438
Thereafter	289
Total minimum payments	6,948
Less: imputed interest	447
Total lease liabilities	6,501
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2022	53,111
2023	56,121
2024	55,896
2025	54,853
Thereafter	246,023
Total minimum payments	501,017
Less: imputed interest	114,072
Total lease liabilities	386,945
Finance Lease, Liability, to be Paid, Year One	2,023
Lessee, Operating Lease, Liability, to be Paid, Year One	$ 35,013

NON-CONTROLLING INTERESTS - Own

NON-CONTROLLING INTERESTS - Ownership Interest in SSE Holdings (Details) - shares	Mar. 31, 2021	Dec. 30, 2020
Noncontrolling Interest [Line Items]
Number of LLC Interests held by Shake Shack Inc. (in shares)	39,103,239	38,717,790
Number of LLC Interests held by non-controlling interest holders (in shares)	2,921,588	2,951,188
Total LLC Interests outstanding (in shares)	42,024,827	41,668,978
Total LLC Interests outstanding (as a percentage)	100.00%	100.00%
Shake Shack Inc.
Noncontrolling Interest [Line Items]
Number of LLC Interests held by Shake Shack Inc. (as a percentage)	93.00%	92.90%
Non-Controlling Interest Holders
Noncontrolling Interest [Line Items]
Number of LLC Interests held by non-controlling interest holders (as a percentage)	7.00%	7.10%

NON-CONTROLLING INTERESTS - Nar

NON-CONTROLLING INTERESTS - Narrative (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Noncontrolling Interest [Line Items]
Non-controlling interest holders' weighted average ownership percentage	7.00%	8.40%
Employee Stock Option
Noncontrolling Interest [Line Items]
Units acquired during the period (in shares)	355,849	77,903

NON-CONTROLLING INTERESTS - Cha

NON-CONTROLLING INTERESTS - Changes in Ownership Interests in SSE Holdings (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Noncontrolling Interest [Line Items]
Net income (loss) attributable to Shake Shack Inc.	$ 1,309	$ (960)
Other comprehensive income:
Net change related to available-for-sale securities	(1)	1
Transfers (to) from non-controlling interests:
Total effect of changes in ownership interest on equity attributable to Shake Shack Inc.	4,704	(341)
Redemption or Exchange of Units
Transfers (to) from non-controlling interests:
Increase (decrease) in additional paid-in capital	36	195
Employee Stock Option
Transfers (to) from non-controlling interests:
Increase (decrease) in additional paid-in capital	$ 3,359	$ 424

NON-CONTROLLING INTERESTS NON-C

NON-CONTROLLING INTERESTS NON-CONTROLLING INTERESTS - Redemption of LLC Interests (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Limited Liability Company
Class of Stock [Line Items]
Number of units redeemed (in shares)	29,600	28,195
Redemptions by NCI Holders | Limited Liability Company
Class of Stock [Line Items]
Number of units redeemed (in shares)	29,600	28,195
Common Stock [Member] | Class A Common Stock
Class of Stock [Line Items]
Shares of Class A common stock issued in connection with redemptions of LLC Interests	29,600	28,195
Common Stock [Member] | Class B Common Stock
Class of Stock [Line Items]
Shares of Class A common stock issued in connection with redemptions of LLC Interests	29,600	28,195
Shares of Class B common stock surrendered and canceled	29,600	28,195

EQUITY-BASED COMPENSATION - Sch

EQUITY-BASED COMPENSATION - Schedule of compensation expense recognized (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 1,681	$ 1,300
Total income tax benefit recognized related to equity-based compensation	67	36
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	20	261
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	414	413
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	1,247	626
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	1,541	1,214
Labor And Related Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 140	$ 86

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020	Dec. 30, 2020
Income Tax Contingency [Line Items]
Effective income tax rate reconciliation (in percentage)	105.50%	(8.80%)
Ownership percentage, weighted average	93.00%	91.60%
Deferred tax asset recognized as a result of investment in partnership	$ 10,204,000
Deferred tax asset related to additional tax basis	300,000
Deferred tax assets, valuation allowance	$ 1,260
Percentage of tax benefits due to equity owners	85.00%
Percentage of tax benefits expected to be realized	15.00%
Consolidated Entity, Ownership By Parent, LLC Units Acquired	29,600
Establishment of liabilities under tax receivable agreement	$ 1,094,000	$ 310,000
Tax receivable agreement payments to related parties	0	$ 6,569,000
Liabilities under tax receivable agreement	234,048,000		$ 232,954,000
Foreign Tax Credit
Income Tax Contingency [Line Items]
Deferred tax assets, valuation allowance	$ 0
Limited Liability Company
Income Tax Contingency [Line Items]
Units acquired during the period (in shares)	385,449
Deferred tax asset, investment in partnership	$ 142,867,000

EARNINGS PER SHARE - Schedule o

EARNINGS PER SHARE - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Numerator:
NET INCOME (LOSS) ATTRIBUTABLE TO SHAKE SHACK INC.	$ 1,309	$ (960)
Reallocation of net loss attributable to non-controlling interests from the assumed conversion of Class B shares	$ (734)	$ (119)
Denominator:
Weighted-average shares of Class A common stock outstanding—basic (in shares)	38,948	34,444
Effect of dilutive securities:
Weighted-average shares of Class A common stock outstanding—diluted (in shares)	42,789	34,444
Earnings per share of Class A common stock—basic (in dollars per share)	$ 0.03	$ (0.03)
Earnings per share of Class A common stock—diluted (in dollars per share)	$ 0.01	$ (0.03)
Performance stock units
Effect of dilutive securities:
Stock options (in shares)	53	0
Restricted stock units
Effect of dilutive securities:
Stock options (in shares)	164	0
Convertible Notes
Effect of dilutive securities:
Stock options (in shares)	451	0
Class B Common Stock
Numerator:
Reallocation of net loss attributable to non-controlling interests from the assumed conversion of Class B shares	$ (734)	$ 0
Effect of dilutive securities:
Stock options (in shares)	2,941	0
Stock options
Effect of dilutive securities:
Stock options (in shares)	232	0

EARNINGS PER SHARE - Antidiluti

EARNINGS PER SHARE - Antidilutive Securities (Details) - Common Stock [Member] - shares	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares (in shares)	1,698	847,207
Performance stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares (in shares)	51,974	179,253
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares (in shares)	0	264,431
Shares of Class B common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares (in shares)	0	3,117,002

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) - USD ($)	1 Months Ended	3 Months Ended
	Feb. 28, 2018	Mar. 31, 2021	Mar. 25, 2020	Dec. 30, 2020	Sep. 30, 2017
Loss Contingencies [Line Items]
Litigation Settlement, Expense	$ 1,200,000	$ 595,000
Loss Contingency Accrual		$ 1,180,000
Percentage of tax benefits due to equity owners		85.00%
Establishment of liabilities under tax receivable agreement		$ 1,094,000	$ 310,000
Tax receivable agreement liability		234,048,000		$ 232,954,000
Retail site
Loss Contingencies [Line Items]
Letters of credit outstanding		$ 130,000
Office building
Loss Contingencies [Line Items]
Letters of credit outstanding					$ 603,000
Renewal term		1 year

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details)	3 Months Ended
	Mar. 31, 2021USD ($)renewal_option	Mar. 25, 2020USD ($)	Dec. 30, 2020USD ($)
Related Party Transaction [Line Items]
Percentage of tax benefits due to equity owners	85.00%
Tax receivable agreement payments to related parties	$ 0	$ 6,569,000
Tax receivable agreement liability	234,048,000		$ 232,954,000
Tax distributions payable to non-controlling interest holders	0		0
Distributions paid to non-controlling interest holders	$ 467,000	305,000
Subsidiary to Affiliated Entity
Related Party Transaction [Line Items]
Number of renewal terms | renewal_option	5
Renewal option period	5 years
Share Our Strength
Related Party Transaction [Line Items]
Amount raised through donations	$ 0
Mobo Systems, Inc. [Member] | Board of Directors Chairman
Related Party Transaction [Line Items]
Expenses from transactions with related party	147,000	52,000
Amounts due to related parties, current	0		0
Concession Income | Subsidiary to Affiliated Entity
Related Party Transaction [Line Items]
Revenue from related parties	0	22,000
Due from related parties, current	0		8,000
Rent Expense | Madison Square Park Conservancy
Related Party Transaction [Line Items]
Expenses from transactions with related party	215,000	219,000
Amounts due to related parties, current	0
Mobo Systems, Inc. | Board of Directors Chairman
Related Party Transaction [Line Items]
Expenses from transactions with related party	462,000	$ 571,000
Amounts due to related parties, current	$ 9,000		$ 9,000