LONG-TERM DEBT - Schedules and Introduction (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Oct. 31, 2016	Sep. 30, 2016	Aug. 31, 2013	Mar. 31, 2012
Debt Schedule [Abstract]
Long-term debt, excluding capital leases	$ 1,651,209		$ 1,685,167
Amount outstanding	1,690,763
Less: current portion of long-term debt	(75,131)		(29,759)
Long-term debt, net of current portion	1,576,078		1,655,408
Discount and debt issuance costs			7,515
Debt issuance costs		$ 2,500
Credit Facility | Senior Secured Credit Facility - Revolving
Debt Schedule [Abstract]
Long-term debt, excluding capital leases	0		13,000
Credit Facility | Senior Secured Credit Facility - Term Loan A, due June 2018
Debt Schedule [Abstract]
Long-term debt, excluding capital leases	0		95,399
Discount and debt issuance costs			1,464
Credit Facility | Senior Secured Credit Facility - Term Loan B, due June 2018
Debt Schedule [Abstract]
Long-term debt, excluding capital leases	0		765,002
Discount and debt issuance costs			11,119
Credit Facility | Senior Secured Credit Facility - Revolving, due October 2021
Debt Schedule [Abstract]
Amount outstanding	0		0
Credit Facility | Senior Secured Credit Facility - Term Loan A, due October 2021, net of discount and debt issuance costs of $7,415 as of September 30, 2017
Debt Schedule [Abstract]
Amount outstanding	387,523		0
Credit Facility | Senior Secured Credit Facility - Term Loan B, due October 2023, net of discount and debt issuance costs of $18,073 as of September 30, 2017
Debt Schedule [Abstract]
Amount outstanding	761,039		0
Discount and debt issuance costs	18,073
Credit Facility | Mohegan Expo Credit Facility, due April 2022, net of debt issuance costs of $1,683 as of September 30, 2017
Debt Schedule [Abstract]
Amount outstanding	13,017		0
Discount and debt issuance costs	1,683
Credit Facility | New Downs Lodging Credit Facility, due November 2019
Debt Schedule [Abstract]
Long-term debt, excluding capital leases	0		20,396
Debt issuance costs	1,260
Senior Unsecured Notes | 2013 9 3/4% Senior Unsecured Notes, due September 2021, net of premium and debt issuance costs of $6,475 as of September 30, 2016
Debt Schedule [Abstract]
Amount outstanding	$ 0		578,525
Discount and debt issuance costs			6,475
Interest rate (as a percent)	9.75%			9.75%
Senior Unsecured Notes | 2016 7 7/8% Senior Unsecured Notes, due October 2024, net of discount and debt issuance costs of $12,383 as of September 30, 2017
Debt Schedule [Abstract]
Amount outstanding	$ 487,617		0
Interest rate (as a percent)	7.875%	7.875%
Debt issuance costs	$ 12,383
Senior Unsecured Notes | 2015 Senior Unsecured Notes, due December 2017, net of debt issuance costs of $1,679 as of September 30, 2016
Debt Schedule [Abstract]
Amount outstanding	0		98,321
Debt issuance costs			1,679
Senior Subordinated Notes | 2012 11% Senior Subordinated Notes, due September 2018, net of discount and debt issuance costs of $875 as of September 30, 2016
Debt Schedule [Abstract]
Amount outstanding	$ 0		99,315
Discount and debt issuance costs			875
Interest rate (as a percent)	11.00%				11.00%
Promissory Notes | 2012 Mohegan Tribe Minor's Trust Promissory Note, due March 2017
Debt Schedule [Abstract]
Long-term debt, excluding capital leases	$ 0		5,500
Promissory Notes | 2013 Mohegan Tribe Promissory Note, due December 2018
Debt Schedule [Abstract]
Long-term debt, excluding capital leases	0		7,420
Other Debt
Debt Schedule [Abstract]
Long-term debt, excluding capital leases	$ 2,013		$ 2,289