General - Basis of Presentation (Details) $ / shares in Units, shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) park $ / shares shares	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2016 USD ($) park $ / shares shares	Jun. 30, 2015 USD ($) $ / shares shares	Dec. 31, 2015 USD ($)
Organization, Consolidation and Presentation of Financial Statements
Number of parks owned or operated | park	18		18
Income Taxes
Valuation allowance | $	$ 91,100,000		$ 91,100,000		$ 88,400,000
Accrued interest and penalties, income taxes | $	0		0		0
Earnings Per Share, Basic and Diluted [Abstract]
Net income (loss) attributable to Six Flags Entertainment Corporation | $	$ 60,887,000	$ 65,532,000	$ 13,952,000	$ (4,794,000)
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Weighted-average common shares outstanding — basic: | shares	93,054	94,834	92,707	94,347
Effect of dilutive stock options and restricted shares | shares	2,358	2,548	2,246	0
Weighted-average common shares outstanding — diluted: | shares	95,412	97,382	94,953	94,347
Earnings (loss) per share — basic: | $ / shares	$ 0.65	$ 0.69	$ 0.15	$ (0.05)
Earnings (loss) per share — diluted: | $ / shares	$ 0.64	$ 0.67	$ 0.15	$ (0.05)
Antidilutive stock options excluded from computation of diluted shares outstanding (in shares) | shares	27	304	306	6,350
Accounts Receivable, Net
Allowance for doubtful accounts | $	$ 11,200,000		$ 11,200,000		$ 2,400,000
United States
Organization, Consolidation and Presentation of Financial Statements
Number of parks owned or operated | park	16		16
Mexico
Organization, Consolidation and Presentation of Financial Statements
Number of parks owned or operated | park	1		1
Canada
Organization, Consolidation and Presentation of Financial Statements
Number of parks owned or operated | park	1		1