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 Dec. 31, 2018	$ 2,099	$ 1,037,640	$ (1,611,334)	$ (71,498)	$ (643,093)
Beginning balance (in shares) at Dec. 31, 2018	83,962,182
Increase (Decrease) in Stockholders' Deficit
Issuance of common stock	$ 7	10,851			10,858
Issuance of common stock (in shares)	283,825
Stock-based compensation		3,891			3,891
Dividends declared to common shareholders			(68,934)		(68,934)
Repurchase of common stock		(4)			(4)
Repurchase of common stock (in shares)	(67)
Net income attributable to Six Flags Entertainment Corporation			(69,132)		(69,132)
Other comprehensive income (loss), net of tax				1,232	1,232
Ending balance at Mar. 31, 2019	$ 2,106	1,052,378	(1,749,400)	(70,266)	(765,182)
Ending balance (in shares) at Mar. 31, 2019	84,245,940
Beginning balance at Dec. 31, 2019	$ 2,116	1,066,223	(1,709,747)	(74,710)	(716,118)
Beginning balance (in shares) at Dec. 31, 2019	84,633,845
Increase (Decrease) in Stockholders' Deficit
Issuance of common stock	$ 1	421			422
Issuance of common stock (in shares)	32,788
Stock-based compensation		4,280			4,280
Dividends declared to common shareholders			(21,164)		(21,164)
Repurchase of common stock		(6)			(6)
Repurchase of common stock (in shares)	(155)
Employee stock purchase plan	$ (1)				(1)
Employee stock purchase plan (in shares)	27
Change in redemption value of partnership units		18			18
Net income attributable to Six Flags Entertainment Corporation			(84,546)		(84,546)
Other comprehensive income (loss), net of tax				(35,713)	(35,713)
Ending balance at Mar. 31, 2020	$ 2,116	$ 1,070,900	$ (1,815,457)	$ (110,423)	$ (852,864)
Ending balance (in shares) at Mar. 31, 2020	84,666,505