Condensed Consolidated Statements of Stockholders Deficit - USD ($) $ in Thousands	Common stock	Capital in excess of par value	Accumulated deficit	Accumulated other comprehensive loss	Total
Beginning balance at Jan. 02, 2022	$ 2,154	$ 1,120,084	$ (2,023,251)	$ (81,187)	$ (982,200)
Beginning balance (in shares) at Jan. 02, 2022	86,162,879
Increase (Decrease) in Equity (Deficit)
Issuance of common stock	$ 7	1,032			1,039
Issuance of common stock (in shares)	303,409
Stock-based compensation		7,448			7,448
Repurchase of common stock	$ (87)	(25,394)	(71,293)		(96,774)
Repurchase of common stock (in shares)	(3,464,385)
Payment of tax withholdings on equity-based compensation through shares withheld		(260)			(260)
Payment of tax withholdings on equity-based compensation through shares withheld (in shares)	(7,340)
Employee stock purchase plan	$ 1	624			625
Employee stock purchase plan (in shares)	31,993
Fresh start valuation adjustment for partnership park units purchased			117		117
Net loss attributable to Six Flags Entertainment Corporation			(20,270)		(20,270)
Net other comprehensive income, net of tax				9,255	9,255
Ending balance at Jul. 03, 2022	$ 2,075	1,103,534	(2,114,697)	(71,932)	(1,081,020)
Ending balance (in shares) at Jul. 03, 2022	83,026,556
Beginning balance at Apr. 03, 2022	$ 2,156	1,124,603	(2,088,913)	(75,622)	(1,037,776)
Beginning balance (in shares) at Apr. 03, 2022	86,248,545
Increase (Decrease) in Equity (Deficit)
Issuance of common stock	$ 5	735			740
Issuance of common stock (in shares)	215,707
Stock-based compensation		3,223			3,223
Repurchase of common stock	$ (87)	(25,394)	(71,293)		(96,774)
Repurchase of common stock (in shares)	(3,464,385)
Payment of tax withholdings on equity-based compensation through shares withheld		(257)			(257)
Payment of tax withholdings on equity-based compensation through shares withheld (in shares)	(5,304)
Employee stock purchase plan	$ 1	624			625
Employee stock purchase plan (in shares)	31,993
Fresh start valuation adjustment for partnership park units purchased			117		117
Net loss attributable to Six Flags Entertainment Corporation			45,392		45,392
Net other comprehensive income, net of tax				3,690	3,690
Ending balance at Jul. 03, 2022	$ 2,075	1,103,534	(2,114,697)	(71,932)	(1,081,020)
Ending balance (in shares) at Jul. 03, 2022	83,026,556
Beginning balance at Jan. 01, 2023	$ 2,079	1,104,051	(1,985,500)	(71,195)	(950,565)
Beginning balance (in shares) at Jan. 01, 2023	83,178,294
Increase (Decrease) in Equity (Deficit)
Issuance of common stock	$ 6	(7)			(1)
Issuance of common stock (in shares)	273,469
Stock-based compensation		5,493			5,493
Payment of tax withholdings on equity-based compensation through shares withheld		(241)			(241)
Payment of tax withholdings on equity-based compensation through shares withheld (in shares)	(9,161)
Employee stock purchase plan	$ 1	483			484
Employee stock purchase plan (in shares)	22,172
Fresh start valuation adjustment for partnership park units purchased			69		69
Net loss attributable to Six Flags Entertainment Corporation			(49,305)		(49,305)
Net other comprehensive income, net of tax				(1,400)	(1,400)
Ending balance at Jul. 02, 2023	$ 2,086	1,109,779	(2,034,736)	(72,595)	(995,466)
Ending balance (in shares) at Jul. 02, 2023	83,464,774
Beginning balance at Apr. 02, 2023	$ 2,082	1,107,258	(2,055,359)	(70,694)	(1,016,713)
Beginning balance (in shares) at Apr. 02, 2023	83,279,300
Increase (Decrease) in Equity (Deficit)
Issuance of common stock	$ 3	(4)			(1)
Issuance of common stock (in shares)	168,809
Stock-based compensation		2,179			2,179
Payment of tax withholdings on equity-based compensation through shares withheld		(137)			(137)
Payment of tax withholdings on equity-based compensation through shares withheld (in shares)	(5,507)
Employee stock purchase plan	$ 1	483			484
Employee stock purchase plan (in shares)	22,172
Fresh start valuation adjustment for partnership park units purchased			69		69
Net loss attributable to Six Flags Entertainment Corporation			20,554		20,554
Net other comprehensive income, net of tax				(1,901)	(1,901)
Ending balance at Jul. 02, 2023	$ 2,086	$ 1,109,779	$ (2,034,736)	$ (72,595)	$ (995,466)
Ending balance (in shares) at Jul. 02, 2023	83,464,774