LONG-TERM DEBT - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jun. 10, 2019	Sep. 30, 2018
Debt Schedule [Abstract]
Long-term debt	$ 1,936,943		$ 1,814,155
Less: current portion of long-term debt	(77,824)		(73,232)
Long-term debt, net of current portion	1,859,119		1,740,923
Credit Facility \| Senior Secured Credit Facility - Revolving
Debt Schedule [Abstract]
Long-term debt	114,000		66,000
Credit Facility \| Senior Secured Credit Facility - Term Loan A
Debt Schedule [Abstract]
Long-term debt	274,370		311,466
Discount and debt issuance costs	4,820		6,661
Credit Facility \| Senior Secured Credit Facility - Term Loan B
Debt Schedule [Abstract]
Long-term debt	806,627		810,430
Discount and debt issuance costs	17,862		20,571
Credit Facility \| Mohegan Expo Credit Facility
Debt Schedule [Abstract]
Long-term debt	29,883		31,980
Discount and debt issuance costs	1,023		1,319
Credit Facility \| Guaranteed Credit Facility
Debt Schedule [Abstract]
Long-term debt	32,416		22,403
Discount and debt issuance costs	1,272		1,262
Credit Facility \| MGE Niagara Credit Facility
Debt Schedule [Abstract]
Long-term debt	75,140		0
Discount and debt issuance costs	1,050	$ 3,100	0
Senior Unsecured Notes \| 2016 7 7/8% Senior Unsecured Notes
Debt Schedule [Abstract]
Long-term debt	490,056		488,967
Discount and debt issuance costs	$ 9,944		11,033
Note stated interest rate	7.875%
Convertible Debenture \| MGE Niagara Credit Facility
Debt Schedule [Abstract]
Long-term debt	$ 30,476		0
Note Payable \| Redemption Note Payable
Debt Schedule [Abstract]
Long-term debt	82,716		81,165
Discount and debt issuance costs	26,344		33,635
Other
Debt Schedule [Abstract]
Long-term debt	$ 1,259		$ 1,744

Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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