Chapter 11 Reorganization (Details) (USD $)	1 Months Ended		8 Months Ended	12 Months Ended		4 Months Ended		1 Months Ended		1 Months Ended
	Jun. 30, 2011	May 31, 2011	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Apr. 30, 2010 Six Flags, Inc. (SFI) and Six Flags Operations Inc. (SFO)	Apr. 30, 2010 Six Flags, Inc. (SFI) and Six Flags Operations Inc. (SFO) Discharge of debt to holders of 2016 Notes	Apr. 30, 2010 Six Flags, Inc. (SFI) and Six Flags Operations Inc. (SFO) Discharge of claims of accredited investors holding unsecured claims and participating in rights offering	Jun. 21, 2010 Six Flags, Inc. (SFI) and Six Flags Operations Inc. (SFO) 2015 Notes	Apr. 30, 2010 Six Flags Entertainment Corporation (Holdings)	Apr. 30, 2010 Six Flags Entertainment Corporation (Holdings) Discharge of debt to holders of 2016 Notes	Apr. 30, 2010 Six Flags Entertainment Corporation (Holdings) Discharge of claims to holders of unsecured claims	Apr. 30, 2010 Six Flags Entertainment Corporation (Holdings) Discharge of claims of accredited investors holding unsecured claims and participating in rights offering	Apr. 30, 2010 Six Flags Entertainment Corporation (Holdings) Issuance of common stock in $75.0 million offering	Apr. 30, 2010 Six Flags Entertainment Corporation (Holdings) Issuance of common stock in $50.0 million offering	Apr. 30, 2010 Six Flags Entertainment Corporation (Holdings) Issuance of common stock for commitment to purchase $25.0 million additional shares under Delayed Draw Equity Purchase	Apr. 30, 2010 Six Flags Entertainment Corporation (Holdings) 2013 Notes	Dec. 31, 2012 Six Flags Entertainment Corporation (Holdings) 2014 Notes	Dec. 31, 2012 Six Flags Entertainment Corporation (Holdings) 2015 Notes
Common Stock
Common stock issued by Holdings (in shares)										54,777,778	4,724,618	5,203,888	34,363,950	6,798,012	3,399,006	288,304
Par value of shares of common stock issued (in dollars per share)				$ 0.025	$ 0.025					$ 0.025
Interest rate (as a percent)							12.25%		4.50%								9.75%	9.625%	4.50%
Stock split ratio	2	2
Aggregate amount of debt repaid in exchange of shares issued							$ 69,500,000
Value of rights offering								505,500,000
Commitment by shareholders to purchase additional shares under Delayed Draw Equity Purchase																25,000,000
Purchase price of shares issued			$ 599,000	$ 40,042,000	$ 9,122,000	$ 805,791,000								$ 75,000,000	$ 50,000,000