Long-Term Indebtedness - Additional Information (Details) $ in Thousands							1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 22, 2020 USD ($)	Oct. 18, 2019 USD ($)	Oct. 17, 2019	Apr. 17, 2019 USD ($)	Apr. 13, 2017 USD ($)	Jun. 16, 2016 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Apr. 30, 2020 USD ($)	Apr. 08, 2020 USD ($)	Apr. 07, 2020 USD ($)	Dec. 31, 2019 USD ($)	Aug. 31, 2019 USD ($)	Jun. 30, 2019 USD ($) agreement
Summary of Long-term debt
Loss on debt extinguishment, net								$ 1,019
Repayments of Debt								117,510	$ 25,000
Proceeds from issuance of debt utilized for extinguishment of existing debt instruments						$ 150,000
Interest Rate Swap
Summary of Long-term debt
Notional amount																$ 300,000
June 2019 Swap Agreements
Summary of Long-term debt
Notional amount							$ 100,000	100,000
Interest Rate Swap Second Agreements
Summary of Long-term debt
Notional amount															$ 400,000
Amended And Restated Revolving Loan
Summary of Long-term debt
Maximum borrowing capacity							350,000	350,000
Amended And Restated Revolving Loan | Subsequent Event
Summary of Long-term debt
Maximum borrowing capacity												$ 481,000	$ 350,000
Incremental borrowing capacity												131,000
Amended And Restated Term Loan B
Summary of Long-term debt
Maximum borrowing capacity							800,000	800,000
Repayments of Debt	$ 315,000
2015 Revolving Loan
Summary of Long-term debt
Maximum borrowing capacity							250,000	250,000
Credit Facility 2015 - Term Loan B
Summary of Long-term debt
Maximum borrowing capacity							700,000	$ 700,000
Credit Facility 2015 - Term Loan B | LIBOR
Summary of Long-term debt
Basis spread on variable rate								1.75%
Credit Facility 2015 Revolving Loan
Summary of Long-term debt
Long-term line of credit														$ 0
Letters of credit outstanding, amount														20,800
Second Amended and Restated Credit Facility
Summary of Long-term debt
Payments of debt issuance costs				$ 8,900
Second Amended and Restated Revolving Loan
Summary of Long-term debt
Maximum borrowing capacity				350,000
Letters of credit outstanding, amount							21,300	$ 21,300
Commitment fee percentage								0.30%
Long-term debt							40,000	$ 40,000
Second Amended and Restated Revolving Loan | Subsequent Event
Summary of Long-term debt
Maximum borrowing capacity												481,000	$ 350,000
Incremental borrowing capacity												$ 131,000
Second Amended and Restated Term Loan B
Summary of Long-term debt
Maximum borrowing capacity				800,000			350,000	350,000
Basis spread reduction		25.00%
Loss on debt extinguishment, net		$ 2,000		$ 6,200
Long-term debt							$ 794,000	$ 794,000						796,000
Interest rate, stated percentage							3.28%	3.28%
Periodic payment										$ 2,000
Annual interest cost savings from borrowing rate reduction		$ 300
Second Amended and Restated Term Loan B | Subsequent Event
Summary of Long-term debt
Maximum borrowing capacity											$ 481,000
Incremental borrowing capacity											131,000
Second Amended and Restated Term Loan B | Interest Rate Swap
Summary of Long-term debt
Number of agreements | agreement																3
Notional amount																$ 300,000
Second Amended and Restated Term Loan B | June 2019 Swap Agreements
Summary of Long-term debt
Notional amount									$ 100,000
Second Amended and Restated Term Loan B | Interest Rate Swap Second Agreements
Summary of Long-term debt
Number of agreements															2
Notional amount															$ 400,000
Second Amended and Restated Term Loan B | LIBOR
Summary of Long-term debt
Basis spread on variable rate		1.75%	2.00%
Senior Unsecured 2024 Notes
Summary of Long-term debt
Loss on debt extinguishment, net								$ 1,000
Long-term debt							$ 949,490	949,490						1,000,000
Debt instrument, face amount						$ 300,000
Interest rate, stated percentage						4.875%
Periodic payment of interest							23,100
Pre-payment								50,500
Senior Unsecured 2024 Notes Add-on
Summary of Long-term debt
Debt instrument, face amount					$ 700,000
Interest rate, stated percentage					4.875%
Periodic payment of interest							23,100
Senior Unsecured 2025 Notes | Subsequent Event | Six Flags Theme Parks Inc.
Summary of Long-term debt
Debt instrument, face amount	$ 725,000										$ 725,000
Interest rate, stated percentage	7.00%										7.00%
Senior Unsecured 2027 Notes
Summary of Long-term debt
Long-term debt							$ 500,000	$ 500,000						$ 500,000
Debt instrument, face amount					$ 500,000
Interest rate, stated percentage					5.50%
Periodic payment of interest					$ 13,800