Long-Term Debt - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Nov. 04, 2021	Sep. 30, 2021
Debt Schedule [Abstract]
Long-term debt, fair value	$ 2,395,000
Less: current portion of long-term debt, fair value	(75,812)
Long-term debt, net of current portion, fair value	2,319,188
Fair value	2,361,492
Long-term debt, book value	2,210,799		$ 1,938,754
Less: current portion of long-term debt, book value	(75,707)		(80,276)
Long-term debt, net of current portion, book value	2,135,092		1,858,478
Unamortized discounts and debt issuance costs	184,201		34,022
MGE Korea Term Loan
Debt Schedule [Abstract]
Stated interest rate		17.00%
Line of Credit | New Senior Secured Credit Facility
Debt Schedule [Abstract]
Long-term debt, fair value	27,000
Long-term debt, book value	27,000		27,000
Line of Credit | Line of Credit
Debt Schedule [Abstract]
Long-term debt, fair value	13,929
Long-term debt, book value	13,929		20,227
Line of Credit | MGE Niagara Credit Facility - Revolving
Debt Schedule [Abstract]
Long-term debt, fair value	11,811
Long-term debt, book value	11,811		27,534
Line of Credit | MGE Niagara Credit Facility - Swingline
Debt Schedule [Abstract]
Long-term debt, fair value	6,655
Long-term debt, book value	6,655		4,333
Line of Credit | MGE Niagara Credit Facility - Term Loan
Debt Schedule [Abstract]
Long-term debt, fair value	68,898
Long-term debt, book value	68,124		68,965
Line of Credit | Inspire Korea Credit Facility
Debt Schedule [Abstract]
Long-term debt, fair value	174,961
Long-term debt, book value	116,126		0
Line of Credit | MGE Korea Term Loan
Debt Schedule [Abstract]
Long-term debt, fair value	275,000
Long-term debt, book value	180,615		0
Line of Credit | Mohegan Expo Credit Facility
Debt Schedule [Abstract]
Long-term debt, fair value	25,286
Long-term debt, book value	25,181		25,697
Line of Credit | Guaranteed Credit Facility
Debt Schedule [Abstract]
Long-term debt, fair value	27,125
Long-term debt, book value	$ 26,626		27,208
Senior Notes | 2021 8% Senior Secured Notes
Debt Schedule [Abstract]
Stated interest rate	8.00%
Long-term debt, fair value	$ 1,175,000
Long-term debt, book value	1,158,569		1,157,731
Senior Notes | 2016 7 7/8% Senior Unsecured Notes
Debt Schedule [Abstract]
Long-term debt, fair value	500,000
Long-term debt, book value	494,067		493,599
Convertible Debenture | MGE Niagara Convertible Debenture
Debt Schedule [Abstract]
Long-term debt, fair value	31,496
Long-term debt, book value	31,496		31,468
Redemption Note Payable | Redemption Note Payable
Debt Schedule [Abstract]
Long-term debt, fair value	56,100
Long-term debt, book value	$ 48,861		53,130
Other | 2016 7 7/8% Senior Unsecured Notes
Debt Schedule [Abstract]
Stated interest rate	7.875%
Other | Other
Debt Schedule [Abstract]
Long-term debt, fair value	$ 1,739
Long-term debt, book value	$ 1,739		$ 1,862