CONDENSED CONSOLIDATED STATEMENT OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 24, 2020	Jun. 30, 2021	Jun. 24, 2020
TOTAL REVENUE	$ 187,460	$ 91,786	$ 342,742	$ 234,956
Shack-level operating expenses:
Food and paper costs	54,917	30,027	99,547	69,591
Labor and related expenses	52,631	30,933	99,013	72,699
Other operating expenses	24,275	14,304	47,419	32,083
Occupancy and related expenses	14,876	12,323	28,787	24,881
General and administrative expenses	20,366	14,017	39,931	30,208
Depreciation and amortization expense	14,472	12,089	28,198	23,857
Pre-opening costs	2,258	1,734	5,834	3,977
Impairment and loss on disposal of assets	358	434	727	2,522
TOTAL EXPENSES	184,153	115,861	349,456	259,818
OPERATING INCOME (LOSS)	3,307	(24,075)	(6,714)	(24,862)
Other income, net	108	394	139	301
Interest expense	(359)	(442)	(874)	(554)
INCOME (LOSS) BEFORE INCOME TAXES	3,056	(24,123)	(7,449)	(25,115)
Income tax expense (benefit)	991	(6,092)	(10,089)	(6,005)
NET INCOME (LOSS)	2,065	(18,031)	2,640	(19,110)
Reallocation of net income (loss) attributable to non-controlling interests from the assumed conversion of Class B shares	121	(1,820)		(1,939)
NET INCOME (LOSS) ATTRIBUTABLE TO SHAKE SHACK INC.	$ 1,944	$ (16,211)	$ 3,253	$ (17,171)
Earnings (loss) per share of Class A common stock:
Basic (in dollars per share)	$ 0.05	$ (0.43)	$ 0.08	$ (0.48)
Diluted (in dollars per share)	$ 0.05	$ (0.43)	$ 0.06	$ (0.48)
Weighted-average shares of Class A common stock outstanding:
Basic (in shares)	39,114	37,309	39,031	35,876
Diluted (in shares)	43,789	37,309	43,289	35,876
Shack sales
TOTAL REVENUE	$ 181,470	$ 89,519	$ 332,138	$ 227,567
Licensing revenue
TOTAL REVENUE	$ 5,990	$ 2,267	$ 10,604	$ 7,389