RELATED PARTY TRANSACTIONS (Details)		1 Months Ended		12 Months Ended
	Feb. 28, 2015 rooms	Mar. 31, 2015 a rooms	Jul. 31, 2008 USD ($)	Sep. 30, 2016 USD ($) employee	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Related Party Transaction [Line Items]
Distributions to the Tribe				$ 53,000,000	$ 50,000,000	$ 50,000,000
Bidding threshold established by ordinance				$ 250,000
Acceptable variance in bid from lowest bid for ordinance to apply				5.00%
Mohegan Tribe
Related Party Transaction [Line Items]
Distributions to the Tribe				$ 53,000,000	50,000,000	50,000,000
Incurred interest expense associated with a related party debt				$ 1,800,000	2,100,000	2,300,000
Term of lease				25 years
Renewable period of additional term				25 years
Monthly payment amount			$ 75,000
Number of employees affiliated with related party | employee				120
Mohegan Sun
Related Party Transaction [Line Items]
Expenses for services provided to related party				$ 30,800,000	28,300,000	27,100,000
Mohegan Sun | Gaming
Related Party Transaction [Line Items]
Expenses for services provided to related party				3,900,000	3,100,000	3,200,000
Mohegan Sun | Advertising, general and administrative
Related Party Transaction [Line Items]
Expenses for services provided to related party				20,900,000	19,800,000	18,700,000
Mohegan Sun | Corporate
Related Party Transaction [Line Items]
Expenses for services provided to related party				6,000,000	5,400,000	5,200,000
Mohegan Tribal Utility Authority
Related Party Transaction [Line Items]
Utilities purchased from related party				$ 16,400,000	$ 17,400,000	$ 19,300,000
Mohegan Tribal Finance Authority
Related Party Transaction [Line Items]
Renewable period of additional term		28 years 4 months
Fourth Amendment, Amount of acres released for use | a		1.2
Fourth Amendment, Amount of rooms to be developed (in room) | rooms	400	400