SEGMENT REPORTING (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2017
Segment Reporting Information [Line Items]
Net revenues	$ 344,903	$ 350,155	$ 1,008,404	$ 1,017,971
Income (loss) from operations	63,904	69,964	174,976	178,808
Capital expenditures incurred			104,643	58,792
Total assets	2,288,996		2,288,996		$ 2,235,681
Corporate and other
Segment Reporting Information [Line Items]
Net revenues	6,239	7,606	14,635	14,624
Income (loss) from operations	(8,090)	(4,942)	(27,737)	(29,533)
Capital expenditures incurred			15,702	14,739
Total assets	340,710		340,710		320,428
Operating segments | Mohegan Sun
Segment Reporting Information [Line Items]
Net revenues	270,434	271,578	793,725	795,775
Income (loss) from operations	61,778	62,630	175,950	178,464
Capital expenditures incurred			82,725	38,891
Total assets	1,374,572		1,374,572		1,333,012
Operating segments | Mohegan Sun Pocono
Segment Reporting Information [Line Items]
Net revenues	68,290	71,031	200,224	207,752
Income (loss) from operations	10,216	12,276	26,763	29,877
Capital expenditures incurred			6,216	5,162
Total assets	573,714		573,714		$ 582,241
Inter-segment revenues
Segment Reporting Information [Line Items]
Net revenues	$ (60)	$ (60)	$ (180)	$ (180)