ORGANIZATION AND BASIS OF PRESENTATION - Schedule of Estimated Fair Value of Financing Facilities and Notes (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Jan. 26, 2021
2021 Senior Unsecured Notes | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Note stated interest rate	8.00%	8.00%
2016 7 7/8% Senior Unsecured Notes | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Note stated interest rate	7.875%
Carrying Value | Fair Value, Inputs, Level 2 | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	$ 2,023,084
Carrying Value | Fair Value, Inputs, Level 2 | New Senior Secured Credit Facility - Revolving | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	107,000
Carrying Value | Fair Value, Inputs, Level 2 | Line of Credit | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	16,015
Carrying Value | Fair Value, Inputs, Level 2 | 2021 Senior Unsecured Notes | Other
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Note value	1,156,117
Carrying Value | Fair Value, Inputs, Level 2 | 2016 7 7/8% Senior Unsecured Notes | Other
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Note value	492,691
Carrying Value | Fair Value, Inputs, Level 2 | MGE Niagara Credit Facility - Revolving | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	27,794
Carrying Value | Fair Value, Inputs, Level 2 | MGE Niagara Credit Facility - Term Loan | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	71,618
Carrying Value | Fair Value, Inputs, Level 3 | MGE Niagara Resorts Convertible Debenture | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	31,764
Carrying Value | Fair Value, Inputs, Level 3 | Mohegan Expo Credit Facility | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	26,725
Carrying Value | Fair Value, Inputs, Level 3 | Guaranteed Credit Facility | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	28,369
Carrying Value | Fair Value, Inputs, Level 3 | Redemption Note Payable | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	61,330
Carrying Value | Fair Value, Inputs, Level 3 | Other | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	3,661
Fair Value | Fair Value, Inputs, Level 2 | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	2,074,619
Fair Value | Fair Value, Inputs, Level 2 | New Senior Secured Credit Facility - Revolving | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	105,529
Fair Value | Fair Value, Inputs, Level 2 | Line of Credit | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	15,795
Fair Value | Fair Value, Inputs, Level 2 | 2021 Senior Unsecured Notes | Other
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Note value	1,180,875
Fair Value | Fair Value, Inputs, Level 2 | 2016 7 7/8% Senior Unsecured Notes | Other
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Note value	520,000
Fair Value | Fair Value, Inputs, Level 2 | MGE Niagara Credit Facility - Revolving | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	27,794
Fair Value | Fair Value, Inputs, Level 2 | MGE Niagara Credit Facility - Term Loan | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	71,618
Fair Value | Fair Value, Inputs, Level 3 | MGE Niagara Resorts Convertible Debenture | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	31,764
Fair Value | Fair Value, Inputs, Level 3 | Mohegan Expo Credit Facility | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	27,159
Fair Value | Fair Value, Inputs, Level 3 | Guaranteed Credit Facility | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	29,094
Fair Value | Fair Value, Inputs, Level 3 | Redemption Note Payable | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	61,330
Fair Value | Fair Value, Inputs, Level 3 | Other | Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit facility value	$ 3,661