General - Basis of Presentation (Details) (USD $)	0 Months Ended		1 Months Ended		3 Months Ended			6 Months Ended
	May 08, 2013	May 05, 2011	Jun. 30, 2013 park	Jun. 30, 2011	Jun. 30, 2013 park	Jun. 30, 2012		Jun. 30, 2013 park	Jun. 30, 2012	Dec. 31, 2012
Number of parks owned or operated			18		18			18
Stock split ratio	2	2	2	2
Dividend in form of number of shares for each outstanding share of common stock	1	1
Ownership interest in joint venture (as a percent)								49.00%
Reorganization Items
(Recoveries) costs and expenses related to the reorganization								$ (180,000)	$ 1,049,000
Net cash paid for reorganization items, entirely constituting professional fees								332,000	996,000
Income Taxes
Valuation allowance related to deferred tax asset, primarily consisting of certain state net operating loss and other tax carryforwards			175,100,000		175,100,000			175,100,000		169,900,000
Liability of accrued interest and penalties attributable to income taxes			0		0			0
Earnings (Loss) Per Common Share
Antidilutive stock options excluded from computation of diluted shares outstanding (in shares)					270,000	600,000		9,236,000	11,000,000
Calculation of earnings per common share
Net income attributable to Six Flags Entertainment Corporation common stockholders					$ 47,361,000	$ 72,265,000
Weighted average common shares outstanding - basic					95,751,000	107,598,000	[1]
Effect of dilutive stock options (in shares)					4,715,000	5,812,000
Weighted average common shares outstanding - diluted (in shares)					100,466,000	113,410,000	[1]
Earnings per share - basic (in dollars per share)					$ 0.49	$ 0.67	[1]
Earnings per share - diluted (in dollars per share)					$ 0.47	$ 0.64	[1]
Maximum
Accounting for the Chapter 11 Filing
Former shareholders' ownership interest in SFI after emerging from bankruptcy (as a percent)								50.00%
United States
Number of parks owned or operated			16		16			16
Mexico
Number of parks owned or operated			1		1			1
Canada
Number of parks owned or operated			1		1			1

[1] All 2012 share and per share amounts have been retroactively adjusted to reflect Holdings' two-for-one stock split in June 2013, as described in Note 2 to these condensed consolidated financial statements.