SEGMENT REPORTING (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) segment	Jun. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)
Segment Reporting [Abstract]
Number of reportable segments (in segment) | segment				2
Segment Reporting Information [Line Items]
Net revenues		$ 350,155	$ 323,427	$ 1,017,971	$ 988,402
Income (loss) from operations		69,964	57,997	178,808	188,331
Interest income		2,784	2,284	8,362	6,469
Interest expense		(27,690)	(33,949)	(86,319)	(102,294)
Loss on modification and early extinguishment of debt	$ (58,900)	(1,094)	(277)	(74,890)	(484)
Loss from unconsolidated affiliates		(288)	(494)	(3,133)	(1,338)
Other income (expense), net		0	(1)	3	(17)
Net income		43,676	25,560	22,831	90,667
(Income) loss attributable to non-controlling interests		104	478	797	(2,225)
Net income attributable to Mohegan Tribal Gaming Authority		43,780	26,038	23,628	88,442
Comprehensive income:
Foreign currency translation		(5,133)	(606)	(8,434)	3,596
Other comprehensive income (loss)		(5,133)	(606)	(8,434)	3,596
Other comprehensive (income) loss attributable to non-controlling interests		2,866	384	4,475	(1,793)
Other comprehensive income (loss) attributable to Mohegan Tribal Gaming Authority		(2,267)	(222)	(3,959)	1,803
Comprehensive income attributable to Mohegan Tribal Gaming Authority		41,513	25,816	19,669	90,245
Capital expenditures incurred				58,792	27,695
Total assets		2,214,969		2,214,969		$ 2,227,962
Mohegan Sun
Segment Reporting Information [Line Items]
Income (loss) from operations		62,630	50,520	178,464	171,251
Comprehensive income:
Capital expenditures incurred				38,891	23,666
Total assets		1,330,081		1,330,081		1,332,231
Mohegan Sun Pocono
Segment Reporting Information [Line Items]
Income (loss) from operations		12,276	11,172	29,877	30,910
Comprehensive income:
Capital expenditures incurred				5,162	3,914
Total assets		586,077		586,077		551,116
Corporate and other
Segment Reporting Information [Line Items]
Income (loss) from operations		(4,942)	(3,695)	(29,533)	(13,830)
Comprehensive income:
Capital expenditures incurred				14,739	115
Total assets		298,811		298,811		$ 344,615
Operating segments | Mohegan Sun
Segment Reporting Information [Line Items]
Net revenues		271,578	244,123	795,775	755,392
Operating segments | Mohegan Sun Pocono
Segment Reporting Information [Line Items]
Net revenues		71,031	76,450	207,752	223,160
Operating segments | Corporate and other
Segment Reporting Information [Line Items]
Net revenues		7,606	4,127	14,624	13,669
Inter-segment revenues
Segment Reporting Information [Line Items]
Net revenues		$ (60)	$ (1,273)	$ (180)	$ (3,819)