Shake Shack (SHAK) 10-Q 7 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document and Entity Information - shares	3 Months Ended
	Mar. 28, 2018	Apr. 25, 2018
Document Information [Line Items]
Document type	10-Q
Amendment flag	false
Document period end date	Mar. 28, 2018
Document fiscal year focus	2,018
Document fiscal period focus	Q1
Entity registrant name	SHAKE SHACK INC.
Entity central index key	1,620,533
Current fiscal year end date	--12-26
Entity filer category	Large Accelerated Filer
Entity current reporting status	Yes
Class A Common Stock
Document Information [Line Items]
Entity common stock, shares outstanding (in shares)		27,647,588
Class B Common Stock
Document Information [Line Items]
Entity common stock, shares outstanding (in shares)		9,205,236

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 28, 2018	Dec. 27, 2017
Current assets:
Cash and cash equivalents	$ 26,624	$ 21,507
Marketable securities	61,128	63,036
Accounts receivable	5,033	5,641
Inventories	1,175	1,258
Prepaid expenses and other current assets	1,689	1,757
Total current assets	95,649	93,199
Property and equipment, net	199,878	187,095
Deferred income taxes, net	200,622	185,914
Other assets	4,145	4,398
TOTAL ASSETS	500,294	470,606
Current liabilities:
Accounts payable	6,738	8,210
Accrued expenses	13,202	11,649
Accrued wages and related liabilities	5,728	6,228
Other current liabilities	7,789	7,937
Total current liabilities	33,457	34,024
Deemed landlord financing	17,030	14,518
Deferred rent	39,461	36,596
Liabilities under tax receivable agreement, net of current portion	171,116	158,436
Other long-term liabilities	6,097	2,553
Total liabilities	267,161	246,127
Commitments and contingencies
Stockholders' equity:
Preferred stock, no par value—10,000,000 shares authorized; none issued and outstanding as of March 28, 2018 and December 27, 2017.	0	0
Additional paid-in capital	163,372	153,105
Retained earnings	18,733	16,399
Accumulated other comprehensive income (loss)	0	(49)
Total stockholders' equity attributable to Shake Shack Inc.	182,142	169,492
Non-controlling interests	50,991	54,987
Total equity	233,133	224,479
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	500,294	470,606
Class A Common Stock
Stockholders' equity:
Common stock	28	27
Class B Common Stock
Stockholders' equity:
Common stock	$ 9	$ 10

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - $ / shares	Mar. 28, 2018	Dec. 27, 2017
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
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)	27,627,553	26,527,477
Common stock, shares, outstanding (in shares)	27,627,553	26,527,477
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)	9,220,236	10,250,007
Common stock, shares, outstanding (in shares)	9,220,236	10,250,007

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENT OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Income Statement [Abstract]
Shack sales	$ 96,089	$ 74,155
Licensing revenue	3,027	2,594
TOTAL REVENUE	99,116	76,749
Shack-level operating expenses:
Food and paper costs	26,955	21,174
Labor and related expenses	26,687	20,460
Other operating expenses	10,759	7,665
Occupancy and related expenses	7,675	6,176
General and administrative expenses	11,809	8,470
Depreciation expense	6,498	4,748
Pre-opening costs	2,029	2,415
Loss on disposal of property and equipment	190	13
TOTAL EXPENSES	92,602	71,121
OPERATING INCOME	6,514	5,628
Other income, net	228	195
Interest expense	(565)	(303)
INCOME BEFORE INCOME TAXES	6,177	5,520
Income tax expense	1,198	1,658
NET INCOME	4,979	3,862
Less: net income attributable to non-controlling interests	1,471	1,595
NET INCOME ATTRIBUTABLE TO SHAKE SHACK INC.	$ 3,508	$ 2,267
Earnings per share of Class A common stock:
Basic (in dollars per share)	$ 0.13	$ 0.09
Diluted (in dollars per share)	$ 0.13	$ 0.09
Weighted-average shares of Class A common stock outstanding:
Basic (in shares)	27,039	25,376
Diluted (in shares)	27,822	25,955

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands		3 Months Ended
		Mar. 28, 2018	Mar. 29, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 4,979	$ 3,862
Available-for-sale securities:
Change in net unrealized holding gains (losses)	[1]	(3)	(9)
Less: reclassification adjustments for net realized losses included in net income	[1]	16	3
Net change		13	(6)
OTHER COMPREHENSIVE INCOME (LOSS)		13	(6)
COMPREHENSIVE INCOME		4,992	3,856
Less: comprehensive income attributable to non-controlling interest		1,474	1,593
COMPREHENSIVE INCOME ATTRIBUTABLE TO SHAKE SHACK INC.		$ 3,518	$ 2,263
[1]	Net of tax benefit (expense) of $0 for the thirteen and thirteen weeks ended March 28, 2018 and March 29, 2017

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (Parenthetical) - USD ($)	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Statement of Comprehensive Income [Abstract]
Income tax benefit	$ 0	$ 0

CONDENSED CONSOLIDATED STATEME7

CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (UNAUDITED) - 3 months ended Mar. 28, 2018 - USD ($) $ in Thousands	Total	Class A Common Stock	Class B Common Stock	Common stockClass A Common Stock	Common stockClass B Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non- Controlling Interest
Beginning balance (shares) at Dec. 27, 2017		26,527,477	10,250,007	26,527,477	10,250,007
Beginning balance at Dec. 27, 2017	$ 224,479			$ 27	$ 10	$ 153,105	$ 16,399	$ (49)	$ 54,987
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,979						3,508		1,471
Other comprehensive income:
Net change related to available-for-sale securities	13							10	3
Equity-based compensation	1,455					1,455
Activity under stock compensation plans (in shares)				70,305
Activity under stock compensation plans	1,476					866			610
Redemption of LLC Interests (in shares)				1,029,771	1,029,771
Redemption of LLC Interests	0			$ 1	$ (1)	5,558			(5,558)
Establishment of liabilities under tax receivable agreement and related changes to deferred tax assets associated with increases in tax basis	2,388					2,388
Distributions paid to non-controlling interest holders	(83)								(83)
Ending balance (shares) at Mar. 28, 2018		27,627,553	9,220,236	27,627,553	9,220,236
Ending balance at Mar. 28, 2018	233,133			$ 28	$ 9	163,372	18,733	0	50,991
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of accounting changes | Adjustments for New Accounting Pronouncement	$ (1,574)						$ (1,174)	$ 39	$ (439)

CONDENSED CONSOLIDATED STATEME8

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
OPERATING ACTIVITIES
Net income (including amounts attributable to non-controlling interests)	$ 4,979	$ 3,862
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation expense	6,498	4,748
Equity-based compensation	1,437	1,249
Deferred income taxes	(305)	(1,009)
Non-cash interest expense	72	71
Loss on sale of marketable securities	16	3
Loss on disposal of property and equipment	190	13
Unrealized loss on available-for-sale securities	38	0
Net loss on sublease	672	0
Changes in operating assets and liabilities:
Accounts receivable	3,111	2,312
Inventories	83	(97)
Prepaid expenses and other current assets	(110)	(505)
Other assets	206	(520)
Accounts payable	0	400
Accrued expenses	1,177	1,029
Accrued wages and related liabilities	(500)	(2,057)
Other current liabilities	(528)	62
Deferred rent	291	164
Other long-term liabilities	1,806	(46)
NET CASH PROVIDED BY OPERATING ACTIVITIES	19,133	9,679
INVESTING ACTIVITIES
Purchases of property and equipment	(17,718)	(13,132)
Purchases of marketable securities	(277)	(325)
Sales of marketable securities	2,144	5,155
NET CASH USED IN INVESTING ACTIVITIES	(15,851)	(8,302)
FINANCING ACTIVITIES
Proceeds from deemed landlord financing	521	293
Payments on deemed landlord financing	(79)	(36)
Distributions paid to non-controlling interest holders	(83)	(355)
Payments under tax receivable agreement	0	(1,471)
Proceeds from stock option exercises	1,476	4,296
NET CASH PROVIDED BY FINANCING ACTIVITIES	1,835	2,727
NET INCREASE IN CASH AND CASH EQUIVALENTS	5,117	4,104
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	21,507	11,607
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 26,624	$ 15,711

NATURE OF OPERATIONS

NATURE OF OPERATIONS	3 Months Ended
	Mar. 28, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
NATURE OF OPERATIONS	NATURE OF OPERATIONS Shake Shack Inc. ("we," "us," "our," "Shake Shack" and the "Company") 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"). W e 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 28, 2018 we owned 75.0% 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, chicken sandwiches, hot dogs, crinkle-cut fries, shakes, frozen custard, beer, wine and more. As of March 28, 2018 , there were 168 Shacks in operation, system-wide, of which 95 were domestic company-operated Shacks, 10 were domestic licensed Shacks and 63

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 28, 2018
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 27, 2017 ("2017 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. Certain reclassifications have been made to prior period amounts to conform to the current year presentation. Operating results for interim periods are not necessarily indicative of the results that may be expected for a full fiscal year. The accompanying Condensed Consolidated Balance Sheet as of December 27, 2017 has been derived from the audited financial statements at that date but does not include all of the disclosures required by GAAP. These interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes thereto included in our 2017 Form 10-K. 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 28, 2018 and December 27, 2017 , the net assets of SSE Holdings were $204,076 and $197,301 , respectively. The assets of SSE Holdings are subject to certain restrictions in SSE Holdings' revolving credit agreements. See Note 8 for more information. Fiscal Year We operate on a 52/53 week fiscal year ending on the last Wednesday in December. Fiscal 2018 contains 52 weeks and ends on December 26, 2018 . Fiscal 2017 contained 52 weeks and ended on December 27, 2017 . 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 us 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 2018. Accounting Standards Update (“ASU”) Description Date Adopted Revenue from Contracts with Customers and related standards (ASU’s 2014-09, 2015-14, 2016-08, 2016-10, 2016-12, 2016-20) This standard supersedes the existing revenue recognition guidance and provides a new framework for recognizing revenue. The core principle of the standard is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. The new standard also requires significantly more comprehensive disclosures than the existing standard. Guidance subsequent to ASU 2014-09 has been issued to clarify various provisions in the standard, including principal versus agent considerations, identifying performance obligations, licensing transactions, as well as various technical corrections and improvements. See Note 3 for more information. December 28, 2017 Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01) For public business entities, this standard requires: (i) certain equity investments to be measured at fair value with changes in fair value recognized in net income; (ii) a qualitative assessment to identify impairment of equity investments without readily determinable fair values; (iii) elimination of the requirement to disclose the method(s) and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost on the balance sheet; (iv) use of the exit price notion when measuring the fair value of financial instruments for disclosure purposes; (v) separate presentation in other comprehensive income of the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments; (vi) separate presentation of financial assets and liabilities by measurement category and form of financial asset in the financial statements; and (vii) an entity to evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity’s other deferred tax assets. The adoption of this standard did not have a material impact to our consolidated financial statements. December 28, 2017 Statement of Cash Flows: Classification of Certain Cash Receipts and Payments (ASU 2016-15) This standard provides guidance on eight specific cash flow issues with the objective of reducing diversity in practice. The adoption of this standard did not have a material impact to our consolidated financial statements. December 28, 2017 Recently Issued Accounting Pronouncements Accounting Standards Update (“ASU”) Description Expected Impact Effective Date Leases (ASU's 2016-02, 2018-01) This standard establishes a new lease accounting model, which introduces the recognition of lease assets and liabilities for those leases classified as operating leases under previous GAAP. It should be applied using a modified retrospective approach, with the option to elect various practical expedients. Early adoption is permitted. We are currently evaluating the provisions of the standard, including optional practical expedients. We are assessing the impact to our accounting policies, processes, disclosures and internal control over financial reporting. We plan to adopt the standard on December 27, 2018. It is likely that the adoption will have a significant impact to our consolidated balance sheet given the number of real estate leases we have. We are still evaluating the expected impact to our consolidated statements of income and cash flows. December 27, 2018

REVENUE

REVENUE	3 Months Ended
	Mar. 28, 2018
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE On December 28, 2017 we adopted ASU 2014-09, Revenue from Contracts with Customers (Topic 606) , using the modified retrospective method applied to those contracts which were not completed as of December 28, 2017. We elected a practical expedient to aggregate the effect of all contract modifications that occurred before the adoption date, which did not have a material impact to our consolidated financial statements. Results for reporting periods beginning on or after December 28, 2017 are presented under Accounting Standards Codification Topic 606 ("ASC 606"). Prior period amounts were not revised and continue to be reported in accordance with ASC Topic 605 ("ASC 605"), the accounting standard then in effect. Upon transition, on December 28, 2017, we recorded a decrease to opening equity of $1,574 , net of tax, of which $1,135 was recognized in retained earnings and $439 in non-controlling interest, with a corresponding increase of $1,769 in other long-term liabilities, a decrease of $68 in other current liabilities, and an increase of $100 to accounts receivable. 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 in exchange for those goods or services. Revenue from Shack sales are 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 are 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 restaurant opening fees are received either in advance of or upon opening the related restaurant. 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 are recognized as the related sales occur. Prior to the adoption of ASC 606, Shack opening fees were recorded as deferred revenue when received and proportionate amounts were recognized as revenue when a licensed Shack opened and all material services and conditions related to the fee were substantially performed. Territory fees were recorded as deferred revenue when received and recognized as revenue on a straight-line basis over the term of the license agreement, which generally began upon execution of the contract. Revenue recognized for the thirteen weeks ended March 28, 2018 under ASC 606 and revenue that would have been recognized for the thirteen weeks ended March 28, 2018 had ASC 605 been applied is as follows: Thirteen Weeks Ended March 28, 2018 As reported under ASC 606 If reported under ASC 605 Increase (decrease) Shack sales $ 96,089 $ 96,089 $ — Licensing revenue 3,027 3,148 (121 ) Total revenue $ 99,116 $ 99,237 $ (121 ) Revenue recognized during the thirteen weeks ended March 28, 2018 (under ASC 606) and March 29, 2017 (under ASC 605) disaggregated by type is as follows: Thirteen Weeks Ended March 28 March 29 Shack sales $ 96,089 $ 74,155 Licensing revenue: Sales-based royalties 2,972 2,400 Initial territory and opening fees 55 194 Total revenue $ 99,116 $ 76,749 The aggregate amount of the transaction price allocated to performance obligations that are unsatisfied (or partially unsatisfied) as of March 28, 2018 is $9,092 . We expect to recognize this amount as revenue over a long-term period, as the license term for each Shack ranges from 10 to 20 years with renewals. 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 28 December 28 Shack sales receivables $ 2,447 $ 2,184 Licensing receivables 1,435 1,522 Gift card liability 1,310 1,472 Deferred revenue, current 306 265 Deferred revenue, long-term 5,417 3,742 Revenue recognized during the period that was included in their respective liability balances at the beginning of the period is as follows: Thirteen Weeks Ended March 28 2018 Gift card liability $ 306 Deferred revenue, current 55

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 28, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Assets and Liabilities Measured at Fair Value on a Recurring Basis The following tables present information about our financial assets and liabilities measured at fair value on a recurring basis as of March 28, 2018 and December 27, 2017 , and indicate the classification within the fair value hierarchy. Cash, Cash Equivalents and Marketable Securities The following tables summarize our cash, cash equivalents and marketable securities by significant investment categories as of March 28, 2018 and December 27, 2017 : March 28, 2018 Cost Basis Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and Cash Equivalents Marketable Securities Cash $ 21,620 $ — $ — $ 21,620 $ 21,620 $ — Level 1: Money market funds 5,004 — — 5,004 5,004 — Mutual funds 61,227 — (99 ) 61,128 — 61,128 Level 2: Corporate debt securities (1) — — — — — — Total $ 87,851 $ — $ (99 ) $ 87,752 $ 26,624 $ 61,128 December 27, 2017 Cost Basis Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and Cash Equivalents Marketable Securities Cash $ 16,138 $ — $ — $ 16,138 $ 16,138 $ — Level 1: Money market funds 5,369 — — 5,369 5,369 — Mutual funds 60,985 — (61 ) 60,924 — 60,924 Level 2: Corporate debt securities (1) 2,125 2 (15 ) 2,112 — 2,112 Total $ 84,617 $ 2 $ (76 ) $ 84,543 $ 21,507 $ 63,036 (1) Corporate debt securities were measured at fair value using a market approach utilizing observable prices for identical securities or securities with similar characteristics and inputs that are observable or can be corroborated by observable market data. On December 28, 2017, we adopted ASU 2016-01, which requires certain equity investments to be measured at fair value with changes in fair value recognized in net income. Net un realized losses on available-for-sale equity securities totaling $38 were included on the Condensed Consolidated Statements of Income during the thirteen weeks ended March 28, 2018 . Net unrealized losses on available-for-sale securities totaling $74 were included in accumulated other comprehensive income (loss) on the Condensed Consolidated Balance Sheet as of December 27, 2017 . The following tables summarize the gross unrealized losses and fair values for those investments that were in an unrealized loss position as of March 28, 2018 and December 27, 2017 , aggregated by investment category and the length of time that individual securities have been in a continuous loss position: March 28, 2018 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Money market funds $ — $ — $ — $ — $ — $ — Mutual funds 61,128 (99 ) — — 61,128 (99 ) Corporate debt securities — — — — — — Total $ 61,128 $ (99 ) $ — $ — $ 61,128 $ (99 ) December 27, 2017 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Money market funds $ — $ — $ — $ — $ — $ — Mutual funds 60,924 (61 ) — — 60,924 (61 ) Corporate debt securities 1,675 (12 ) 162 (3 ) 1,837 (15 ) Total $ 62,599 $ (73 ) $ 162 $ (3 ) $ 62,761 $ (76 ) A summary of other income from available-for-sale securities recognized during the thirteen weeks ended March 28, 2018 and March 29, 2017 is as follows: Thirteen Weeks Ended March 28 March 29 Available-for-sale securities: Dividend income $ 275 $ 178 Interest income 7 20 Realized gain (loss) on sale of investments (16 ) (3 ) Unrealized gain (loss) on available-for-sale equity securities (38 ) — Total other income, net $ 228 $ 195 A summary of available-for-sale securities sold and gross realized gains and losses recognized during the thirteen weeks ended March 28, 2018 and March 29, 2017 is as follows: Thirteen Weeks Ended March 28 March 29 Available-for-sale securities: Gross proceeds from sales and redemptions $ 2,144 $ 155 Cost basis of sales and redemptions 2,160 158 Gross realized gains included in net income 2 — Gross realized losses included in net income (18 ) (3 ) Amounts reclassified out of accumulated other comprehensive loss 16 3 Realized gains and losses are determined on a specific identification method and are included in other income, net on the Condensed Consolidated Statements of Income . We periodically review our marketable securities for other-than-temporary impairment. We consider factors such as the duration, severity and the reason for the decline in value, the potential recovery period and our intent to sell. As of March 28, 2018 and December 27, 2017 , the declines in the market value of our marketable securities investment portfolio were considered to be temporary in nature. Other Financial Instruments The carrying value of our other financial instruments, including accounts receivable, accounts payable, and accrued expenses as of March 28, 2018 and December 27, 2017 approximated their fair value due to the short-term nature of these financial instruments. 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 and indefinite-lived intangible assets. There were no impairments recognized during the thirteen weeks ended March 28, 2018 and March 29, 2017

INVENTORIES

INVENTORIES	3 Months Ended
	Mar. 28, 2018
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES Inventories as of March 28, 2018 and December 27, 2017 consisted of the following: March 28 December 27 Food $ 795 $ 874 Wine 66 69 Beer 76 85 Beverages 128 111 Retail merchandise 110 119 Inventories $ 1,175 $ 1,258

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	3 Months Ended
	Mar. 28, 2018
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT	PROPERTY AND EQUIPMENT Property and equipment as of March 28, 2018 and December 27, 2017 consisted of the following: March 28 December 27 Leasehold improvements $ 173,422 $ 166,963 Landlord funded assets 10,949 7,472 Equipment 33,059 31,608 Furniture and fixtures 10,298 10,128 Computer equipment and software 13,231 12,721 Construction in progress (includes landlord funded assets under construction) 22,860 16,458 Property and equipment, gross 263,819 245,350 Less: accumulated depreciation 63,941 58,255 Property and equipment, net $ 199,878 $ 187,095

SUPPLEMENTAL BALANCE SHEET INFO

SUPPLEMENTAL BALANCE SHEET INFORMATION	3 Months Ended
	Mar. 28, 2018
Supplemental Balance Sheet Disclosures [Abstract]
SUPPLEMENTAL BALANCE SHEET INFORMATION	SUPPLEMENTAL BALANCE SHEET INFORMATION The components of other current liabilities as of March 28, 2018 and December 27, 2017 are as follows: March 28 December 27 Sales tax payable $ 2,827 $ 1,813 Current portion of liabilities under tax receivable agreement 937 937 Gift card liability 1,310 1,472 Other 2,715 3,715 Other current liabilities $ 7,789 $ 7,937

DEBT

DEBT	3 Months Ended
	Mar. 28, 2018
Debt Disclosure [Abstract]
DEBT	DEBT In January 2015, we executed a Third Amended and Restated Credit Agreement, which became effective on February 4, 2015 (together with the prior agreements and amendments, and as further amended, the "Revolving Credit Facility"), which provides for a revolving total commitment amount of $50,000 , of which $20,000 is available immediately. The Revolving Credit Facility will mature and all amounts outstanding will be due and payable five years from the effective date. The Revolving Credit Facility permits the issuance of letters of credit upon our request of up to $10,000 . Borrowings under the Revolving Credit Facility bear interest at either: (i) LIBOR plus a percentage ranging from 2.3% to 3.3% or (ii) the prime rate plus a percentage ranging from 0.0% to 0.8% , depending on the type of borrowing made under the Revolving Credit Facility. As of March 28, 2018 and December 27, 2017 , there were no amounts outstanding under the Revolving Credit Facility. As of March 28, 2018 , we had $19,317 of availability under the Revolving Credit Facility, after giving effect to $683 in outstanding letters of credit. The Revolving Credit Facility is 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' wholly-owned domestic subsidiaries (with certain exceptions). The Revolving Credit Facility contains a number of covenants that, among other things, limit our ability to, subject to specified exceptions, incur additional debt; incur additional liens and contingent liabilities; sell or dispose of assets; merge with or acquire other companies; liquidate or dissolve ourselves; pay dividends or make distributions; engage in businesses that are not in a related line of business; make loans, advances or guarantees; engage in transactions with affiliates; and make investments. In addition, the Revolving Credit Facility contains certain cross-default provisions. We are required to maintain a specified consolidated fixed-charge coverage ratio and a specified funded net debt to adjusted EBITDA ratio, both as defined under the Revolving Credit Facility. As of March 28, 2018 , we were in compliance with all covenants. As of March 28, 2018 and December 27, 2017 we had deemed landlord financing liabilities of $17,030 and $14,518 , respectively, for certain leases where we are involved in the construction of leased assets and are considered the accounting owner of the construction project. Total interest costs incurred were $609 and $324 for the thirteen weeks ended March 28, 2018 and March 29, 2017 , respectively. Total amounts capitalized into property and equipment were $44 and $21 for the thirteen weeks ended March 28, 2018 and March 29, 2017

NON-CONTROLLING INTERESTS

NON-CONTROLLING INTERESTS	3 Months Ended
	Mar. 28, 2018
Noncontrolling Interest [Abstract]
NON-CONTROLLING INTERESTS	NON-CONTROLLING INTERESTS We 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 28, 2018 and December 27, 2017 . March 28, 2018 December 27, 2017 LLC Interests Ownership% LLC Interests Ownership % Number of LLC Interests held by Shake Shack Inc. 27,627,553 75.0 % 26,527,477 72.1 % Number of LLC Interests held by non-controlling interest holders 9,220,236 25.0 % 10,250,007 27.9 % Total LLC Interests outstanding 36,847,789 100.0 % 36,777,484 100.0 % The weighted average ownership percentages for the applicable reporting periods are used to attribute net income and other comprehensive income 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 28, 2018 and March 29, 2017 was 26.5% and 30.4% , respectively. The following table summarizes the effects of changes in ownership of SSE Holdings on our equity during the thirteen weeks ended March 28, 2018 and March 29, 2017 . Thirteen Weeks Ended March 28 March 29 Net income attributable to Shake Shack Inc. $ 3,508 $ 2,267 Other comprehensive income (loss): Net change related to available-for-sale securities 10 (4 ) Transfers (to) from non-controlling interests: Increase in additional paid-in capital as a result of the redemption of LLC Interests 5,558 1,322 Increase in additional paid-in capital as a result of activity under stock compensation plans 866 2,870 Total effect of changes in ownership interest on equity attributable to Shake Shack Inc. $ 9,942 $ 6,455 During the thirteen weeks ended March 28, 2018 and March 29, 2017 , an aggregate of 1,029,771 and 324,000 LLC Interests, respectively, were redeemed by non-controlling interest holders for newly-issued shares of Class A common stock, and we received 1,029,771 and 324,000 LLC Interests in connection with these redemptions for the thirteen weeks ended March 28, 2018 and March 29, 2017 , respectively, increasing our total ownership interest in SSE Holdings. During the thirteen weeks ended March 28, 2018 and March 29, 2017 , we received an aggregate of 70,305 and 206,491

EQUITY-BASED COMPENSATION

EQUITY-BASED COMPENSATION	3 Months Ended
	Mar. 28, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
EQUITY-BASED COMPENSATION	EQUITY-BASED COMPENSATION A summary of equity-based compensation expense recognized during the thirteen weeks ended March 28, 2018 and March 29, 2017 is as follows: Thirteen Weeks Ended March 28 March 29 Stock options $ 827 $ 964 Performance stock units 454 285 Restricted stock units 156 — Equity-based compensation expense $ 1,437 $ 1,249 Total income tax benefit recognized related to equity-based compensation $ 38 $ 51 Amounts are included in general and administrative expense and labor and related expenses on the Condensed Consolidated Statements of Income

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 28, 2018
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. Income Tax Expense A reconciliation of income tax expense computed at the U.S. federal statutory income tax rate to the recognized income tax expense is as follows: Thirteen Weeks Ended March 28 March 29 Expected U.S. federal income taxes at statutory rate $ 1,297 21.0 % $ 1,932 35.0 % State and local income taxes, net of federal benefit 412 6.7 % 349 6.3 % Foreign withholding taxes 531 8.6 % 186 3.4 % Tax credits (277 ) (4.5 )% (130 ) (2.4 )% Non-controlling interest (454 ) (7.3 )% (679 ) (12.3 )% Other (311 ) (5.0 )% — — % Income tax expense $ 1,198 19.4 % $ 1,658 30.0 % Our effective income tax rates for the thirteen weeks ended March 28, 2018 and March 29, 2017 were 19.4% and 30.0% , respectively. The decrease was primarily driven by the reduction of the U.S. federal corporate income tax rate from 35% to 21% due to the enactment of the Tax Cuts and Jobs Act of 2017 (the "TCJA"), partially offset by the increase in our ownership interest in SSE Holdings, which increases our share of the taxable income of SSE Holdings, and higher foreign withholding taxes. Our weighted-average ownership interest in SSE Holdings was 73.5% and 69.6% for the thirteen weeks ended March 28, 2018 and March 29, 2017 , respectively. Deferred Tax Assets and Liabilities During the thirteen weeks ended March 28, 2018 , we acquired an aggregate of 1,100,076 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 $10,302 associated with the basis difference in our investment in SSE Holdings upon acquisition of these LLC Interests. As of March 28, 2018 , the total deferred tax asset related to the basis difference in our investment in SSE Holdings was $148,056 . 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 28, 2018 , the total valuation allowance established against the deferred tax asset to which this portion relates was $8,806 . During the thirteen weeks ended March 28, 2018 , we also recognized $3,458 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" 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 28, 2018 , 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 the eventual sale of our interest in SSE Holdings) are more likely than not to be realized. As such, no additional valuation allowance was recognized. Uncertain Tax Positions No uncertain tax positions existed as of March 28, 2018 . Shake Shack Inc. was formed in September 2014 and did not engage in any operations prior to the IPO and related organizational transactions. Shake Shack Inc. first filed tax returns for tax year 2014, which is the first tax year subject to examination by taxing authorities for U.S. federal and state income tax purposes. Additionally, although SSE Holdings is treated as a partnership for U.S. federal and state income taxes purposes, it is still required to file an annual U.S. Return of Partnership Income, which is subject to examination by the Internal Revenue Service ("IRS"). The statute of limitations has expired for tax years through 2013 for SSE Holdings. 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 28, 2018 , we acquired an aggregate of 1,029,771 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 $12,680 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. No payments were made to the members of SSE Holdings pursuant to the Tax Receivable Agreement during the thirteen weeks ended March 28, 2018 . During the thirteen weeks ended March 29, 2017 , payments of $1,471 , inclusive of interest, were made to the members of SSE Holdings pursuant to the Tax Receivable Agreement. As of March 28, 2018 , the total amount of TRA Payments due under the Tax Receivable Agreement, was $172,053 , of which $937 was included in other current liabilities on the Condensed Consolidated Balance Sheet. See Note 14

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 28, 2018
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE Basic earnings per share of Class A common stock is computed by dividing net income attributable to Shake Shack Inc. by the weighted-average number of shares of Class A common stock outstanding during the period. Diluted earnings per share of Class A common stock is computed by dividing net income attributable to Shake Shack Inc. by the weighted-average number of shares of Class A common stock outstanding adjusted to give effect to potentially dilutive securities. The following table sets forth reconciliations of the numerators and denominators used to compute basic and diluted earnings per share of Class A common stock for the thirteen weeks ended March 28, 2018 and March 29, 2017 . Thirteen Weeks Ended March 28 March 29 Numerator: Net income $ 4,979 $ 3,862 Less: net income attributable to non-controlling interests 1,471 1,595 Net income attributable to Shake Shack Inc. $ 3,508 $ 2,267 Denominator: Weighted-average shares of Class A common stock outstanding—basic 27,039 25,376 Effect of dilutive securities: Stock options 702 552 Performance stock units 70 27 Restricted stock units 11 — Weighted-average shares of Class A common stock outstanding—diluted 27,822 25,955 Earnings per share of Class A common stock—basic $ 0.13 $ 0.09 Earnings per share of Class A common stock—diluted $ 0.13 $ 0.09 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 per share of Class B common stock under the two-class method has not been presented. Shares of our Class B common stock are, however, considered potentially dilutive shares of Class A common stock. After evaluating the potential dilutive effect under the if-converted and two-class methods, the 9,220,236 shares of Class B common stock outstanding as of March 28, 2018 and the 10,929,592 share of Class B common stock outstanding as of March 29, 2017

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	3 Months Ended
	Mar. 28, 2018
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 28, 2018 and March 29, 2017 : Thirteen Weeks Ended March 28 March 29 Cash paid for: Income taxes, net of refunds $ 854 $ 1,093 Interest, net of amounts capitalized 563 19 Non-cash investing activities: Accrued purchases of property and equipment 7,302 4,415 Capitalized landlord assets for leases where we are deemed the accounting owner 2,327 4,545 Capitalized equity-based compensation 18 40 Non-cash financing activities: Class A common stock issued in connection with the redemption of LLC Interests 1 — Cancellation of Class B common stock in connection with the redemption of LLC Interests (1 ) — Establishment of liabilities under tax receivable agreement 12,680 6,357

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 28, 2018
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 2035. 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 charges and utilities. As security under the terms of several of our leases, we are obligated under letters of credit totaling $160 as of March 28, 2018 . The letters of credit expire in April 2019 and February 2026. In addition, in December 2013, we entered into an irrevocable standby letter of credit in conjunction with our home office lease in the amount of $80 . The letter of credit expires in September 2018 and renews automatically for one -year periods through September 2019. In September 2017, we entered into an irrevocable standby letter of credit in conjunction with our new home office lease in the amount of $603 . The letter of credit expires in August 2018 and renews automatically for one -year periods through January 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 We are subject to various legal and regulatory 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 28, 2018 , the amount of ultimate liability with respect to these matters was not material. Liabilities under Tax Receivable Agreement As described in Note 11 , we are a party to the Tax Receivable Agreement under which we are contractually committed to pay certain of the members of SSE Holdings 85% of the amount of any tax benefits that we actually realize, or in some cases are deemed to realize, as a result of certain transactions. We are not obligated to make any payments under the Tax Receivable Agreement until the tax benefits associated with the transactions that gave rise to the payments are realized. Amounts payable under the Tax Receivable Agreement are contingent upon, among other things, (i) generation of future taxable income over the term of the Tax Receivable Agreement and (ii) future changes in tax laws. If we do not generate sufficient taxable income in the aggregate over the term of the Tax Receivable Agreement to utilize the tax benefits, then we would not be required to make the related TRA Payments. During the thirteen weeks ended March 28, 2018 and March 29, 2017 , we recognized liabilities totaling $12,680 and $6,357 , respectively, relating to our obligations under the Tax Receivable Agreement, after concluding that it was probable that we would have sufficient future taxable income over the term of the Tax Receivable Agreement to utilize the related tax benefits. As of March 28, 2018 and December 27, 2017 , our total obligations under the Tax Receivable Agreement, including accrued interest, were $172,053 and $159,373

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	3 Months Ended
	Mar. 28, 2018
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. USHG, LLC Effective January 2015, we entered into an Amended and Restated Management Services Agreement with USHG, LLC ("USHG"), in which USHG provides reduced management services to SSE Holdings comprised of executive leadership from members of its senior management, advisory and development services and limited leadership development and human resources services. The initial term of the Amended and Restated Management Services Agreement is through December 31, 2019, with renewal periods. Amounts paid to USHG for general corporate expenses during the thirteen weeks ended March 28, 2018 and March 29, 2017 were $2 and $5 , respectively. These amounts are included in general and administrative expenses on the Condensed Consolidated Statements of Income . Total amounts payable to USHG as of March 28, 2018 were $1 , which is included in other current liabilities on the Condensed Consolidated Balance Sheets . No amounts were payable to USHG as of December 27, 2017 . No amounts were due from USHG as of March 28, 2018 and December 27, 2017 . Daily Provisions For a period of time in fiscal 2017, we purchased coffee cake from the restaurant Daily Provisions to offer as a breakfast item at our Madison Square Park Shack. No amounts were paid to Daily Provisions during the thirteen weeks ended March 28, 2018 and March 29, 2017 . No amounts were payable to Daily provisions as of March 28, 2018 and December 27, 2017 . 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. The agreement expires in January 2027 and includes five consecutive five -year renewal options at HYSE's option. As consideration for these rights, HYSE pays us a license fee based on a percentage of net food sales, as defined in the MLA. HYSE also pays us a percentage of profits on sales of branded beverages, as defined in the MLA. Amounts paid to us by HYSE for the thirteen weeks ended March 28, 2018 and March 29, 2017 were $47 and $20 , respectively. These amounts are included in licensing revenue on the Condensed Consolidated Statements of Income . Total amounts due from HYSE as of March 28, 2018 and December 27, 2017 were $24 and $18 , respectively, which are included in prepaid expenses and other current assets on the Condensed Consolidated Balance Sheets . 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. Amounts paid to Madison Square Park Conservancy as rent amounted to $267 and $199 for the thirteen weeks ended March 28, 2018 and March 29, 2017 , respectively. These amounts are included in occupancy and related expenses on the Condensed Consolidated Statements of Income . No amounts were due to MSP Conservancy as of March 28, 2018 and December 27, 2017 . No amounts were paid to us from MSP Conservancy during the thirteen weeks ended March 28, 2018 . Amounts paid to us during the thirteen weeks ended March 29, 2017 totaled $200 . No amounts were due to us from MSP Conservancy as of March 28, 2018 and December 27, 2017 . Share Our Strength The Chairman of our Board of Directors serves as a director of Share Our Strength, for which Shake Shack holds the "Great American Shake Sale" every year during the month of May to raise money and awareness for childhood hunger. During the Great American Shake Sale, we encourage guests to donate money to Share Our Strength's No Kid Hungry campaign in exchange for a coupon for a free cake-themed shake. All of the guest donations we collect go directly to Share Our Strength. No amounts have been raised for the thirteen weeks ended March 28, 2018 and March 29, 2017 . Mobo Systems, Inc. The Chairman of our Board of Directors serves as a director of Mobo Systems, Inc. (also known as "Olo"), a platform we use in connection with our mobile ordering application. Amounts paid to Olo during the thirteen weeks ended March 28, 2018 and March 29, 2017 were $25 and $18 , respectively, which are included in other operating expenses on the Condensed Consolidated Statements of Income . No amounts were payable to Olo as of March 28, 2018 and December 27, 2017 . Square, Inc. In July 2017, our Chief Executive Officer joined 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 Shacks, sales for certain off-site events and in connection with our kiosk technology. Additionally, in March 2017 and October 2017, we partnered with Caviar, Square’s food ordering service, for a limited-time delivery promotion. Amounts paid to Square during the thirteen weeks ended March 28, 2018 were $43 , which are included in other operating expenses on the Condensed Consolidated Statements of Income . No amounts were paid to Square during the thirteen weeks ended March 29, 2017 . No amounts were payable to Square as of March 28, 2018 and December 27, 2017 . Tax Receivable Agreement As described in Note 11 , 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. No payments were made to the members of SSE Holdings pursuant to the Tax Receivable Agreement during the thirteen weeks ended March 28, 2018 . During the thirteen weeks ended March 29, 2017 , payments totaling $1,471 , inclusive of interest, were made to the members of SSE Holdings pursuant to the Tax Receivable Agreement. As of March 28, 2018 and December 27, 2017 , total amounts due under the Tax Receivable Agreement were $172,053 and $159,373 , respectively. 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 . During the thirteen weeks ended March 28, 2018 and March 29, 2017 distributions paid to non-controlling interest holders were $83 and $355 , respectively. No tax distributions were payable to non-controlling interest holders as of March 28, 2018 and December 27, 2017

SUMMARY OF SIGNIFICANT ACCOUN24

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 28, 2018
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 27, 2017 ("2017 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. Certain reclassifications have been made to prior period amounts to conform to the current year presentation. Operating results for interim periods are not necessarily indicative of the results that may be expected for a full fiscal year. The accompanying Condensed Consolidated Balance Sheet as of December 27, 2017 has been derived from the audited financial statements at that date but does not include all of the disclosures required by GAAP. These interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes thereto included in our 2017 Form 10-K. 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 28, 2018 and December 27, 2017 , the net assets of SSE Holdings were $204,076 and $197,301 , respectively. The assets of SSE Holdings are subject to certain restrictions in SSE Holdings' revolving credit agreements. See Note 8 for more information.
Fiscal Year	Fiscal Year We operate on a 52/53 week fiscal year ending on the last Wednesday in December. Fiscal 2018 contains 52 weeks and ends on December 26, 2018 . Fiscal 2017 contained 52 weeks and ended on December 27, 2017
Use of Estimates	Use of EstimatesThe preparation of these condensed consolidated financial statements in conformity with GAAP requires us 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 and Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements We adopted the Accounting Standards Updates (“ASUs”) summarized below in fiscal 2018. Accounting Standards Update (“ASU”) Description Date Adopted Revenue from Contracts with Customers and related standards (ASU’s 2014-09, 2015-14, 2016-08, 2016-10, 2016-12, 2016-20) This standard supersedes the existing revenue recognition guidance and provides a new framework for recognizing revenue. The core principle of the standard is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. The new standard also requires significantly more comprehensive disclosures than the existing standard. Guidance subsequent to ASU 2014-09 has been issued to clarify various provisions in the standard, including principal versus agent considerations, identifying performance obligations, licensing transactions, as well as various technical corrections and improvements. See Note 3 for more information. December 28, 2017 Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01) For public business entities, this standard requires: (i) certain equity investments to be measured at fair value with changes in fair value recognized in net income; (ii) a qualitative assessment to identify impairment of equity investments without readily determinable fair values; (iii) elimination of the requirement to disclose the method(s) and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost on the balance sheet; (iv) use of the exit price notion when measuring the fair value of financial instruments for disclosure purposes; (v) separate presentation in other comprehensive income of the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments; (vi) separate presentation of financial assets and liabilities by measurement category and form of financial asset in the financial statements; and (vii) an entity to evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity’s other deferred tax assets. The adoption of this standard did not have a material impact to our consolidated financial statements. December 28, 2017 Statement of Cash Flows: Classification of Certain Cash Receipts and Payments (ASU 2016-15) This standard provides guidance on eight specific cash flow issues with the objective of reducing diversity in practice. The adoption of this standard did not have a material impact to our consolidated financial statements. December 28, 2017 Recently Issued Accounting Pronouncements Accounting Standards Update (“ASU”) Description Expected Impact Effective Date Leases (ASU's 2016-02, 2018-01) This standard establishes a new lease accounting model, which introduces the recognition of lease assets and liabilities for those leases classified as operating leases under previous GAAP. It should be applied using a modified retrospective approach, with the option to elect various practical expedients. Early adoption is permitted. We are currently evaluating the provisions of the standard, including optional practical expedients. We are assessing the impact to our accounting policies, processes, disclosures and internal control over financial reporting. We plan to adopt the standard on December 27, 2018. It is likely that the adoption will have a significant impact to our consolidated balance sheet given the number of real estate leases we have. We are still evaluating the expected impact to our consolidated statements of income and cash flows. December 27, 2018

REVENUE (Tables)

REVENUE (Tables)	3 Months Ended
	Mar. 28, 2018
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	Revenue recognized for the thirteen weeks ended March 28, 2018 under ASC 606 and revenue that would have been recognized for the thirteen weeks ended March 28, 2018 had ASC 605 been applied is as follows: Thirteen Weeks Ended March 28, 2018 As reported under ASC 606 If reported under ASC 605 Increase (decrease) Shack sales $ 96,089 $ 96,089 $ — Licensing revenue 3,027 3,148 (121 ) Total revenue $ 99,116 $ 99,237 $ (121 ) thirteen weeks ended March 28, 2018 (under ASC 606) and March 29, 2017 (under ASC 605) disaggregated by type is as follows: Thirteen Weeks Ended March 28 March 29 Shack sales $ 96,089 $ 74,155 Licensing revenue: Sales-based royalties 2,972 2,400 Initial territory and opening fees 55 194 Total revenue $ 99,116 $ 76,749
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 28 December 28 Shack sales receivables $ 2,447 $ 2,184 Licensing receivables 1,435 1,522 Gift card liability 1,310 1,472 Deferred revenue, current 306 265 Deferred revenue, long-term 5,417 3,742 Thirteen Weeks Ended March 28 2018 Gift card liability $ 306 Deferred revenue, current 55

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 28, 2018
Fair Value Disclosures [Abstract]
Schedule of Cash and Cash Equivalents	The following tables summarize our cash, cash equivalents and marketable securities by significant investment categories as of March 28, 2018 and December 27, 2017 : March 28, 2018 Cost Basis Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and Cash Equivalents Marketable Securities Cash $ 21,620 $ — $ — $ 21,620 $ 21,620 $ — Level 1: Money market funds 5,004 — — 5,004 5,004 — Mutual funds 61,227 — (99 ) 61,128 — 61,128 Level 2: Corporate debt securities (1) — — — — — — Total $ 87,851 $ — $ (99 ) $ 87,752 $ 26,624 $ 61,128 December 27, 2017 Cost Basis Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and Cash Equivalents Marketable Securities Cash $ 16,138 $ — $ — $ 16,138 $ 16,138 $ — Level 1: Money market funds 5,369 — — 5,369 5,369 — Mutual funds 60,985 — (61 ) 60,924 — 60,924 Level 2: Corporate debt securities (1) 2,125 2 (15 ) 2,112 — 2,112 Total $ 84,617 $ 2 $ (76 ) $ 84,543 $ 21,507 $ 63,036 (1)
Schedule of Unrealized Loss on Investments	The following tables summarize the gross unrealized losses and fair values for those investments that were in an unrealized loss position as of March 28, 2018 and December 27, 2017 , aggregated by investment category and the length of time that individual securities have been in a continuous loss position: March 28, 2018 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Money market funds $ — $ — $ — $ — $ — $ — Mutual funds 61,128 (99 ) — — 61,128 (99 ) Corporate debt securities — — — — — — Total $ 61,128 $ (99 ) $ — $ — $ 61,128 $ (99 ) December 27, 2017 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Money market funds $ — $ — $ — $ — $ — $ — Mutual funds 60,924 (61 ) — — 60,924 (61 ) Corporate debt securities 1,675 (12 ) 162 (3 ) 1,837 (15 ) Total $ 62,599 $ (73 ) $ 162 $ (3 ) $ 62,761 $ (76 )
Schedule of Other Income From Available for Sale Securities	A summary of other income from available-for-sale securities recognized during the thirteen weeks ended March 28, 2018 and March 29, 2017 is as follows: Thirteen Weeks Ended March 28 March 29 Available-for-sale securities: Dividend income $ 275 $ 178 Interest income 7 20 Realized gain (loss) on sale of investments (16 ) (3 ) Unrealized gain (loss) on available-for-sale equity securities (38 ) — Total other income, net $ 228 $ 195
Schedule of Available-for-sale Securities and Gross Realized Gains and Losses	A summary of available-for-sale securities sold and gross realized gains and losses recognized during the thirteen weeks ended March 28, 2018 and March 29, 2017 is as follows: Thirteen Weeks Ended March 28 March 29 Available-for-sale securities: Gross proceeds from sales and redemptions $ 2,144 $ 155 Cost basis of sales and redemptions 2,160 158 Gross realized gains included in net income 2 — Gross realized losses included in net income (18 ) (3 ) Amounts reclassified out of accumulated other comprehensive loss 16 3

INVENTORIES (Tables)

INVENTORIES (Tables)	3 Months Ended
	Mar. 28, 2018
Inventory Disclosure [Abstract]
Inventories	Inventories as of March 28, 2018 and December 27, 2017 consisted of the following: March 28 December 27 Food $ 795 $ 874 Wine 66 69 Beer 76 85 Beverages 128 111 Retail merchandise 110 119 Inventories $ 1,175 $ 1,258

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	3 Months Ended
	Mar. 28, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property and equipment as of March 28, 2018 and December 27, 2017 consisted of the following: March 28 December 27 Leasehold improvements $ 173,422 $ 166,963 Landlord funded assets 10,949 7,472 Equipment 33,059 31,608 Furniture and fixtures 10,298 10,128 Computer equipment and software 13,231 12,721 Construction in progress (includes landlord funded assets under construction) 22,860 16,458 Property and equipment, gross 263,819 245,350 Less: accumulated depreciation 63,941 58,255 Property and equipment, net $ 199,878 $ 187,095

SUPPLEMENTAL BALANCE SHEET IN29

SUPPLEMENTAL BALANCE SHEET INFORMATION (Tables)	3 Months Ended
	Mar. 28, 2018
Supplemental Balance Sheet Disclosures [Abstract]
Supplemental Balance Sheet Information	The components of other current liabilities as of March 28, 2018 and December 27, 2017 are as follows: March 28 December 27 Sales tax payable $ 2,827 $ 1,813 Current portion of liabilities under tax receivable agreement 937 937 Gift card liability 1,310 1,472 Other 2,715 3,715 Other current liabilities $ 7,789 $ 7,937

NON-CONTROLLING INTERESTS (Tabl

NON-CONTROLLING INTERESTS (Tables)	3 Months Ended
	Mar. 28, 2018
Noncontrolling Interest [Abstract]
Schedule of Ownership Interests in SSE Holdings	The following table summarizes the ownership interest in SSE Holdings as of March 28, 2018 and December 27, 2017 . March 28, 2018 December 27, 2017 LLC Interests Ownership% LLC Interests Ownership % Number of LLC Interests held by Shake Shack Inc. 27,627,553 75.0 % 26,527,477 72.1 % Number of LLC Interests held by non-controlling interest holders 9,220,236 25.0 % 10,250,007 27.9 % Total LLC Interests outstanding 36,847,789 100.0 % 36,777,484 100.0 %
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 28, 2018 and March 29, 2017 . Thirteen Weeks Ended March 28 March 29 Net income attributable to Shake Shack Inc. $ 3,508 $ 2,267 Other comprehensive income (loss): Net change related to available-for-sale securities 10 (4 ) Transfers (to) from non-controlling interests: Increase in additional paid-in capital as a result of the redemption of LLC Interests 5,558 1,322 Increase in additional paid-in capital as a result of activity under stock compensation plans 866 2,870 Total effect of changes in ownership interest on equity attributable to Shake Shack Inc. $ 9,942 $ 6,455

EQUITY-BASED COMPENSATION (Tabl

EQUITY-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 28, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Equity-Based Compensation Expense Recognized	A summary of equity-based compensation expense recognized during the thirteen weeks ended March 28, 2018 and March 29, 2017 is as follows: Thirteen Weeks Ended March 28 March 29 Stock options $ 827 $ 964 Performance stock units 454 285 Restricted stock units 156 — Equity-based compensation expense $ 1,437 $ 1,249 Total income tax benefit recognized related to equity-based compensation $ 38 $ 51

INCOME TAXES (Tables)

INCOME TAXES (Tables)	3 Months Ended
	Mar. 28, 2018
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of income tax expense computed at the U.S. federal statutory income tax rate to the recognized income tax expense is as follows: Thirteen Weeks Ended March 28 March 29 Expected U.S. federal income taxes at statutory rate $ 1,297 21.0 % $ 1,932 35.0 % State and local income taxes, net of federal benefit 412 6.7 % 349 6.3 % Foreign withholding taxes 531 8.6 % 186 3.4 % Tax credits (277 ) (4.5 )% (130 ) (2.4 )% Non-controlling interest (454 ) (7.3 )% (679 ) (12.3 )% Other (311 ) (5.0 )% — — % Income tax expense $ 1,198 19.4 % $ 1,658 30.0 %

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 28, 2018
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 per share of Class A common stock for the thirteen weeks ended March 28, 2018 and March 29, 2017 . Thirteen Weeks Ended March 28 March 29 Numerator: Net income $ 4,979 $ 3,862 Less: net income attributable to non-controlling interests 1,471 1,595 Net income attributable to Shake Shack Inc. $ 3,508 $ 2,267 Denominator: Weighted-average shares of Class A common stock outstanding—basic 27,039 25,376 Effect of dilutive securities: Stock options 702 552 Performance stock units 70 27 Restricted stock units 11 — Weighted-average shares of Class A common stock outstanding—diluted 27,822 25,955 Earnings per share of Class A common stock—basic $ 0.13 $ 0.09 Earnings per share of Class A common stock—diluted $ 0.13 $ 0.09

SUPPLEMENTAL CASH FLOW INFORM34

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	3 Months Ended
	Mar. 28, 2018
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 28, 2018 and March 29, 2017 : Thirteen Weeks Ended March 28 March 29 Cash paid for: Income taxes, net of refunds $ 854 $ 1,093 Interest, net of amounts capitalized 563 19 Non-cash investing activities: Accrued purchases of property and equipment 7,302 4,415 Capitalized landlord assets for leases where we are deemed the accounting owner 2,327 4,545 Capitalized equity-based compensation 18 40 Non-cash financing activities: Class A common stock issued in connection with the redemption of LLC Interests 1 — Cancellation of Class B common stock in connection with the redemption of LLC Interests (1 ) — Establishment of liabilities under tax receivable agreement 12,680 6,357

NATURE OF OPERATIONS (Details)

NATURE OF OPERATIONS (Details) - Restaurant	Mar. 28, 2018	Dec. 27, 2017
Class of Stock [Line Items]
Ownership percent of noncontrolling interest	75.00%	72.10%
Number of restaurants	168
United States | Company-operated
Class of Stock [Line Items]
Number of restaurants	95
United States | Licensed
Class of Stock [Line Items]
Number of restaurants	10
Non-United States | Licensed
Class of Stock [Line Items]
Number of restaurants	63

SUMMARY OF SIGNIFICANT ACCOUN36

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	Mar. 28, 2018	Dec. 27, 2017
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Net assets held by SSE holders	$ 204,076	$ 197,301

REVENUE - Narrative (Details)

REVENUE - Narrative (Details) - USD ($) $ in Thousands	Dec. 28, 2017	Mar. 28, 2018	Dec. 27, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other long-term liabilities		$ 6,097	$ 2,553
Other current liabilities		7,789	$ 7,937
Revenue, remaining performance obligation		$ 9,092
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Opening equity	$ 1,574
Other long-term liabilities	1,769
Other current liabilities	68
Accounts receivable	100
Retained Earnings | Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Opening equity	1,135
Noncontrolling Interest | Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Opening equity	$ 439

REVENUE - Schedule of Revenue R

REVENUE - Schedule of Revenue Recognized (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 99,116	$ 76,749
If reported under ASC 605
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	99,237
Accounting Standards Update 2014-09 | Increase (decrease)
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(121)
Shack sales
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	96,089	$ 74,155
Shack sales | If reported under ASC 605
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	96,089
Shack sales | Accounting Standards Update 2014-09 | Increase (decrease)
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0
Licensing revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3,027
Licensing revenue | If reported under ASC 605
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3,148
Licensing revenue | Accounting Standards Update 2014-09 | Increase (decrease)
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ (121)

REVENUE - Schedule of Disaggreg

REVENUE - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 99,116	$ 76,749
Shack sales
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	96,089	74,155
Sales-based royalties
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,972	2,400
Initial territory and opening fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 55	$ 194

REVENUE - Schedule of Respectiv

REVENUE - Schedule of Respective Liability Balances (Details) - USD ($) $ in Thousands	Mar. 28, 2018	Dec. 28, 2017	Dec. 27, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Gift card liability	$ 1,310	$ 1,472	$ 1,472
Deferred revenue, current	306	265
Deferred revenue, long-term	5,417	3,742
Shack sales
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract with customer, asset, net	2,447	2,184
Licensing receivables
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract with customer, asset, net	$ 1,435	$ 1,522

REVENUE - Liability Balance (De

REVENUE - Liability Balance (Details) - USD ($) $ in Thousands	Mar. 28, 2018	Dec. 28, 2017	Dec. 27, 2017
Disaggregation of Revenue [Line Items]
Gift card liability	$ 1,310	$ 1,472	$ 1,472
Deferred revenue, current	306	$ 265
Accounting Standards Update 2014-09
Disaggregation of Revenue [Line Items]
Gift card liability	306
Deferred revenue, current	$ 55

FAIR VALUE MEASUREMENTS - Cash,

FAIR VALUE MEASUREMENTS - Cash, Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 28, 2018	Dec. 27, 2017	Mar. 29, 2017	Dec. 28, 2016
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	$ 26,624	$ 21,507	$ 15,711	$ 11,607
Total cost basis including Mutual Funds	87,851	84,617
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(99)	(76)
Cash and cash equivalents fair value	26,624	21,507
Fair value of marketable securities	61,128	63,036
Fair Value	87,752	84,543
Level 1 | Mutual funds
Schedule of Available-for-sale Securities [Line Items]
Mutual funds	61,227	60,985
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(99)	(61)
Fair value of marketable securities	61,128	60,924
Level 2 | Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Corporate debt securities	0	2,125
Gross Unrealized Gains	0	2
Gross Unrealized Losses	0	(15)
Fair value of marketable securities	0	2,112
Cash
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	21,620	16,138
Cash and cash equivalents fair value	21,620	16,138
Money market funds | Level 1
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	5,004	5,369
Cash and cash equivalents fair value	$ 5,004	$ 5,369

FAIR VALUE MEASUREMENTS - Addit

FAIR VALUE MEASUREMENTS - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 28, 2018	Mar. 29, 2017	Dec. 27, 2017
Fair Value Disclosures [Abstract]
Net unrealized gain (loss)	$ (38,000)		$ (74,000)
Asset impairment charges	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Unrea

FAIR VALUE MEASUREMENTS - Unrealized Loss on Investments (Details) - USD ($) $ in Thousands	Mar. 28, 2018	Dec. 27, 2017
Gain (Loss) on Investments [Line Items]
Fair Value (less than 12 months)	$ 61,128	$ 62,599
Unrealized Loss (less than 12 months)	(99)	(73)
Fair Value (12 months or greater)	0	162
Unrealized Loss (12 months or greater)	0	(3)
Fair Value	61,128	62,761
Unrealized Loss	(99)	(76)
Mutual funds
Gain (Loss) on Investments [Line Items]
Fair Value (less than 12 months)	61,128	60,924
Unrealized Loss (less than 12 months)	(99)	(61)
Fair Value (12 months or greater)	0	0
Unrealized Loss (12 months or greater)	0	0
Fair Value	61,128	60,924
Unrealized Loss	(99)	(61)
Corporate debt securities
Gain (Loss) on Investments [Line Items]
Fair Value (less than 12 months)	0	1,675
Unrealized Loss (less than 12 months)	0	(12)
Fair Value (12 months or greater)	0	162
Unrealized Loss (12 months or greater)	0	(3)
Fair Value	0	1,837
Unrealized Loss	$ 0	$ (15)

FAIR VALUE MEASUREMENTS - Other

FAIR VALUE MEASUREMENTS - Other Income From Available For Sale Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Available-for-sale securities
Total other income, net	$ 228	$ 195
Available-for-sale Securities
Available-for-sale securities
Dividend income	275	178
Interest income	7	20
Realized gain (loss) on sale of investments	(16)	(3)
Unrealized gain (loss) on available-for-sale equity securities	(38)	0
Total other income, net	$ 228	$ 195

FAIR VALUE MEASUREMENTS - Avail

FAIR VALUE MEASUREMENTS - Available for Sale Securities and Gross Realized Gains and Losses (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 28, 2018	Mar. 29, 2017
Available-for-sale securities:
Gross proceeds from sales and redemptions		$ 2,144	$ 155
Cost basis of sales and redemptions		2,160	158
Gross realized gains included in net income		2	0
Gross realized losses included in net income		(18)	(3)
Amounts reclassified out of accumulated other comprehensive loss	[1]	$ 16	$ 3
[1]	Net of tax benefit (expense) of $0 for the thirteen and thirteen weeks ended March 28, 2018 and March 29, 2017

INVENTORIES (Details)

INVENTORIES (Details) - USD ($) $ in Thousands	Mar. 28, 2018	Dec. 27, 2017
Inventory [Line Items]
Inventories	$ 1,175	$ 1,258
Food
Inventory [Line Items]
Inventories	795	874
Wine
Inventory [Line Items]
Inventories	66	69
Beer
Inventory [Line Items]
Inventories	76	85
Beverages
Inventory [Line Items]
Inventories	128	111
Retail merchandise
Inventory [Line Items]
Inventories	$ 110	$ 119

PROPERTY AND EQUIPMENT (Details

PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	Mar. 28, 2018	Dec. 27, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 263,819	$ 245,350
Less: accumulated depreciation	63,941	58,255
Property and equipment, net	199,878	187,095
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	173,422	166,963
Landlord funded assets
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,949	7,472
Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	33,059	31,608
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,298	10,128
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	13,231	12,721
Construction in progress (includes landlord funded assets under construction)
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 22,860	$ 16,458

SUPPLEMENTAL BALANCE SHEET IN49

SUPPLEMENTAL BALANCE SHEET INFORMATION (Details) - USD ($) $ in Thousands	Mar. 28, 2018	Dec. 28, 2017	Dec. 27, 2017
Other Liabilities, Current
Sales tax payable	$ 2,827		$ 1,813
Current portion of liabilities under tax receivable agreement	937		937
Gift card liability	1,310	$ 1,472	1,472
Other	2,715		3,715
Other current liabilities	$ 7,789		$ 7,937

DEBT (Details)

DEBT (Details) - USD ($)	Sep. 27, 2017	Feb. 04, 2015	Mar. 28, 2018	Mar. 29, 2017	Dec. 27, 2017
Debt Instrument [Line Items]
Deemed landlord financing			$ 17,030,000		$ 14,518,000
Interest costs incurred			609,000	$ 324,000
Interest costs capitalized			44,000	$ 21,000
Notes payable
Debt Instrument [Line Items]
Notes payable			0
Third Amendment and Restated Credit Arrangement | Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 50,000,000
Current borrowing capacity		$ 20,000,000
Term to maturity		5 years
Amount available under revolving credit facility			19,317,000
Third Amendment and Restated Credit Arrangement | Letter of credit | Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 10,000,000
Current borrowing capacity			$ 683,000
Third Amendment and Restated Credit Arrangement | Minimum | Line of credit | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate	2.30%
Third Amendment and Restated Credit Arrangement | Minimum | Line of credit | Prime rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.00%
Third Amendment and Restated Credit Arrangement | Maximum | Line of credit | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate	3.30%
Third Amendment and Restated Credit Arrangement | Maximum | Line of credit | Prime rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.80%

NON-CONTROLLING INTERESTS - Own

NON-CONTROLLING INTERESTS - Ownership Interest in SSE Holdings (Details) - shares	Mar. 28, 2018	Dec. 27, 2017
Noncontrolling Interest [Abstract]
Number of LLC Interests held by Shake Shack Inc. (in shares)	27,627,553	26,527,477
Number of LLC Interests held by non-controlling interest holders (in shares)	9,220,236	10,250,007
Total LLC Interests outstanding (in shares)	36,847,789	36,777,484
Number of LLC Interests held by Shake Shack Inc. (as a percentage)	75.00%	72.10%
Number of LLC Interests held by non-controlling interest holders (as a percentage)	25.00%	27.90%
Total LLC Interests outstanding (as a percentage)	100.00%	100.00%

NON-CONTROLLING INTERESTS - Nar

NON-CONTROLLING INTERESTS - Narrative (Details) - shares	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Noncontrolling Interest [Line Items]
Non-controlling interest holders' weighted average ownership percentage	26.50%	30.40%
Number of units redeemed (in shares)	1,029,771	324,000
Units acquired during the period (in shares)	1,100,076
Redemption or Exchange of Units
Noncontrolling Interest [Line Items]
Units acquired during the period (in shares)	1,029,771	324,000
Employee Stock Option
Noncontrolling Interest [Line Items]
Units acquired during the period (in shares)	70,305	206,491

NON-CONTROLLING INTERESTS - Ch

NON-CONTROLLING INTERESTS - Changes in Ownership Interests in SSE Holdings (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Noncontrolling Interest [Line Items]
Net income attributable to Shake Shack Inc.	$ 3,508	$ 2,267
Other comprehensive income (loss):
Net change related to available-for-sale securities	13	(6)
Transfers (to) from non-controlling interests:
Total effect of changes in ownership interest on equity attributable to Shake Shack Inc.	9,942	6,455
Redemption or Exchange of Units
Transfers (to) from non-controlling interests:
Increase (decrease) in additional paid-in capital	5,558	1,322
Employee Stock Option
Transfers (to) from non-controlling interests:
Increase (decrease) in additional paid-in capital	866	2,870
Net change related to available-for-sale securities
Other comprehensive income (loss):
Net change related to available-for-sale securities	$ 10	$ (4)

EQUITY-BASED COMPENSATION - Sch

EQUITY-BASED COMPENSATION - Schedule of compensation expense recognized (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 1,437	$ 1,249
Total income tax benefit recognized related to equity-based compensation	38	51
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	827	964
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	454	285
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 156	$ 0

INCOME TAXES - Reconciliation o

INCOME TAXES - Reconciliation of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Income Tax Disclosure [Abstract]
Expected U.S. federal income taxes at statutory rate	$ 1,297	$ 1,932
Expected U.S. federal income taxes at statutory rate, percentage	21.00%	35.00%
State and local income taxes, net of federal benefit	$ 412	$ 349
State and local income taxes, net of federal benefit, percentage	6.70%	6.30%
Foreign withholding taxes	$ 531	$ 186
Foreign withholding taxes, percentage	8.60%	3.40%
Tax credits	$ (277)	$ (130)
Tax credits, percentage	(4.50%)	(2.40%)
Non-controlling interest	$ (454)	$ (679)
Non-controlling interest, percentage	(7.30%)	(12.30%)
Other	$ (311)	$ 0
Other, percentage	(5.00%)	0.00%
Income tax expense	$ 1,198	$ 1,658
Income tax expense, percentage	19.40%	30.00%

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017	Dec. 27, 2017
Income Tax Contingency [Line Items]
Effective income tax rate reconciliation (in percentage)	19.40%	30.00%
Ownership percentage, weighted average	73.50%	69.60%
Units acquired during the period (in shares)	1,100,076
Deferred tax asset recognized as a result of investment in partnership	$ 10,302,000
Deferred tax asset, investment in partnership	148,056,000
Valuation allowance, deferred tax asset	8,806,000
Deferred tax asset related to additional tax basis	3,458,000
Uncertain tax positions	$ 0
Percentage of tax benefits due to equity owners	85.00%
Percentage of tax benefits expected to be realized	15.00%
Establishment of liabilities under tax receivable agreement	$ 12,680,000	$ 6,357,000
Tax receivable agreement payments to related parties	0	$ 1,471,000
Liabilities under tax receivable agreement	172,053,000		$ 159,373,000
Current portion of liabilities under tax receivable agreement	$ 937,000		$ 937,000
Redemption or Exchange of Units
Income Tax Contingency [Line Items]
Units acquired during the period (in shares)	1,029,771	324,000

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. 28, 2018	Mar. 29, 2017
Numerator:
Net income	$ 4,979	$ 3,862
Less: net income attributable to non-controlling interests	1,471	1,595
NET INCOME ATTRIBUTABLE TO SHAKE SHACK INC.	$ 3,508	$ 2,267
Denominator:
Weighted-average shares of Class A common stock outstanding—basic (in shares)	27,039	25,376
Effect of dilutive securities:
Weighted-average shares of Class A common stock outstanding—diluted (in shares)	27,822	25,955
Earnings per share of Class A common stock—basic (in dollars per share)	$ 0.13	$ 0.09
Earnings per share of Class A common stock—diluted (in dollars per share)	$ 0.13	$ 0.09
Performance stock units
Effect of dilutive securities:
Stock options (in shares)	70	27
Restricted stock units
Effect of dilutive securities:
Stock options (in shares)	11	0
Stock options
Effect of dilutive securities:
Stock options (in shares)	702	552

EARNINGS PER SHARE - Antidilut

EARNINGS PER SHARE - Antidilutive Securities (Details) - shares	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Shares of Class B common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares (in shares)	9,220,236	10,929,592

SUPPLEMENTAL CASH FLOW INFORM59

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017
Cash paid for:
Income taxes, net of refunds	$ 854	$ 1,093
Interest, net of amounts capitalized	563	19
Non-cash investing activities:
Accrued purchases of property and equipment	7,302	4,415
Capitalized landlord assets for leases where we are deemed the accounting owner	2,327	4,545
Capitalized equity-based compensation	18	40
Non-cash financing activities:
Establishment of liabilities under tax receivable agreement	12,680	6,357
Redemption or Exchange of Units | Class A Common Stock
Non-cash financing activities:
Class A common stock issued in connection with the redemption of LLC Interests	1	0
Redemption or Exchange of Units | Class B Common Stock
Non-cash financing activities:
Cancellation of Class B common stock in connection with the redemption of LLC Interests	$ (1)	$ 0

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2018	Mar. 29, 2017	Dec. 27, 2017	Sep. 30, 2017	Dec. 31, 2013
Loss Contingencies [Line Items]
Percentage of tax benefits due to equity owners	85.00%
Establishment of liabilities under tax receivable agreement	$ 12,680	$ 6,357
Tax receivable agreement liability	172,053		$ 159,373
Retail site
Loss Contingencies [Line Items]
Letters of credit outstanding	$ 160
Office building
Loss Contingencies [Line Items]
Letters of credit outstanding				$ 603	$ 80
Renewal term	1 year

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details)	3 Months Ended
	Mar. 28, 2018USD ($)renewal_option	Mar. 29, 2017USD ($)	Dec. 27, 2017USD ($)
Related Party Transaction [Line Items]
Percentage of tax benefits due to equity owners	85.00%
Tax receivable agreement payments to related parties	$ 0	$ 1,471,000
Tax receivable agreement liability	172,053,000		$ 159,373,000
Distributions paid to non-controlling interest holders	83,000	355,000
Tax distributions payable to non-controlling interest holders	0		0
Affiliated Entity
Related Party Transaction [Line Items]
Amount paid to USHG for general corporate expenses	2,000	5,000
Amounts due to related parties, current	1,000		0
Due from related parties, current	0		0
Daily Provisions
Related Party Transaction [Line Items]
Amounts due to related parties, current and noncurrent	0		0
Amounts of transaction	$ 0	0
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]
Charitable campaign flow through	$ 0	0
Concession Income | Subsidiary to Affiliated Entity
Related Party Transaction [Line Items]
Due from related parties, current	24,000		18,000
Revenue from related parties	47,000	20,000
Rent Expense | Madison Square Park Conservancy
Related Party Transaction [Line Items]
Amounts due to related parties, current	0		0
Revenues from transactions with related party	0	200,000
Expenses from transactions with related party	267,000	199,000
Tenant Improvement Allowance | Madison Square Park Conservancy
Related Party Transaction [Line Items]
Amount due from MSP conservancy	0		0
Mobo Systems, Inc. | Board of Directors Chairman
Related Party Transaction [Line Items]
Amounts due to related parties, current	0		0
Expenses from transactions with related party	25,000	18,000
Square, Inc | Board of Directors Chairman
Related Party Transaction [Line Items]
Amounts due to related parties, current	0		$ 0
Expenses from transactions with related party	$ 43,000	$ 0