LONG-TERM DEBT - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Debt Schedule [Abstract]
Long-term debt	$ 2,060,882	$ 1,970,010
Less: current portion of long-term debt	(33,585)	(75,355)
Long-term debt, net of current portion	2,027,297	1,894,655
Credit Facility \| Senior Secured Credit Facility - Revolving
Debt Schedule [Abstract]
Long-term debt	247,000	197,000
Credit Facility \| Senior Secured Credit Facility - Term Loan A
Debt Schedule [Abstract]
Long-term debt	220,416	227,710
Debt issuance costs	3,149	4,199
Credit Facility \| Senior Secured Credit Facility - Term Loan B
Debt Schedule [Abstract]
Long-term debt	792,220	792,829
Debt issuance costs	19,248	20,809
Credit Facility \| Main Street Term Loan Facility
Debt Schedule [Abstract]
Long-term debt	48,127	0
Debt issuance costs	1,873
Credit Facility \| MGE Niagara Resorts Credit Facility - Revolving
Debt Schedule [Abstract]
Long-term debt	27,464	26,187
Credit Facility \| MGE Niagara Credit Facility - Term Loan
Debt Schedule [Abstract]
Long-term debt	71,721	69,297
Debt issuance costs	864	847
Credit Facility \| Mohegan Expo Credit Facility
Debt Schedule [Abstract]
Long-term debt	27,240	27,750
Debt issuance costs	544	658
Credit Facility \| Guaranteed Credit Facility
Debt Schedule [Abstract]
Long-term debt	28,950	29,529
Debt issuance costs	800	877
Credit Facility \| Mohegan Tribe Subordinated Loan
Debt Schedule [Abstract]
Long-term debt	5,000	5,000
Senior Notes \| 2016 7 7/8% Senior Unsecured Notes
Debt Schedule [Abstract]
Long-term debt	492,252	491,821
Debt issuance costs	7,748	8,179
Convertible Debenture \| MGE Niagara Resorts Convertible Debenture
Debt Schedule [Abstract]
Long-term debt	31,388	29,928
Note Payable to Banks \| Redemption Note Payable
Debt Schedule [Abstract]
Long-term debt	65,289	69,099
Debt issuance costs	$ 13,771	15,701
Other \| 2016 7 7/8% Senior Unsecured Notes
Debt Schedule [Abstract]
Note stated interest rate	7.875%
Other \| Other
Debt Schedule [Abstract]
Long-term debt	$ 3,815	$ 3,860

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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Amount of unamortized debt discount (premium) and debt issuance costs.

+ References

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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