OTHER INTANGIBLE ASSETS, NET - Schedule of Other Current Assets and Other Current Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Finite-Lived Intangible Assets [Line Items]
Subtotal	$ 333,985	$ 460,834
Less: accumulated amortization	(6,144)	(5,569)
Other intangible assets, net	327,841	455,265
Mohegan Sun trademark
Finite-Lived Intangible Assets [Line Items]
Other indefinite-lived intangible assets	119,692	119,692
Mohegan Sun Pocono slot machine, table game, interactive gaming and sports wagering licenses
Finite-Lived Intangible Assets [Line Items]
Other indefinite-lived intangible assets	171,904	298,500
MGE Niagara Resorts Casino Operating and Services Agreement rights
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, gross	$ 16,751	16,753
Useful life	21 years
Other
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, gross	$ 25,638	$ 25,889