LONG-TERM DEBT - Credit Facilities (Details) (USD $)			0 Months Ended	9 Months Ended		9 Months Ended															9 Months Ended
	Jun. 30, 2013	Sep. 30, 2012	Mar. 06, 2012 Credit Facility Bank Credit Facility, due March 2015	Jun. 30, 2013 Credit Facility Bank Credit Facility, due March 2015	Sep. 30, 2012 Credit Facility Bank Credit Facility, due March 2015	Jun. 30, 2013 Credit Facility Bank Credit Facility, due March 2015 Minimum	Jun. 30, 2013 Credit Facility Bank Credit Facility, due March 2015 Maximum	Jun. 30, 2013 Credit Facility Bank Credit Facility, due March 2015 Base Rate Revolving Loans Minimum	Jun. 30, 2013 Credit Facility Bank Credit Facility, due March 2015 Base Rate Revolving Loans Maximum	Jun. 30, 2013 Credit Facility Bank Credit Facility, due March 2015 Eurodollar Rate Revolving Loans Minimum	Jun. 30, 2013 Credit Facility Bank Credit Facility, due March 2015 Eurodollar Rate Revolving Loans Maximum	Jun. 30, 2013 Credit Facility Bank Credit Facility, due March 2015 Base Rate Term Loans	Jun. 30, 2013 Credit Facility Bank Credit Facility, due March 2015 Eurodollar Rate Term Loans	Jun. 30, 2013 Credit Facility Term Loan Credit Facility	Sep. 30, 2012 Credit Facility Term Loan Credit Facility	Mar. 06, 2012 Credit Facility Term Loan Credit Facility	Jun. 30, 2013 Credit Facility Term Loan Credit Facility Base Rate Term Loans	Jun. 30, 2013 Credit Facility Term Loan Credit Facility Eurodollar Rate Term Loans	Jun. 30, 2013 Credit Facility Bank of America, N.A. Line of Credit	Sep. 30, 2012 Credit Facility Bank of America, N.A. Line of Credit	Jun. 30, 2013 Credit Facility Mohegan Tribe Credit Facility	Sep. 30, 2012 Credit Facility Mohegan Tribe Credit Facility	Jun. 30, 2012 Credit Facility Mohegan Tribe Credit Facility	Jun. 30, 2013 Credit Facility Downs Lodging Credit Facility	Sep. 30, 2012 Credit Facility Downs Lodging Credit Facility	Jun. 30, 2013 Credit Facility Letter of Credit Bank Credit Facility, due March 2015	Mar. 06, 2012 Credit Facility Letter of Credit Bank Credit Facility, due March 2015	Jun. 30, 2013 Credit Facility Revolving Loans Bank Credit Facility, due March 2015	Jun. 30, 2013 Downs Lodging, LLC Credit Facility Downs Lodging Credit Facility	Sep. 30, 2012 Downs Lodging, LLC Credit Facility Downs Lodging Credit Facility	Jul. 31, 2012 Downs Lodging, LLC Credit Facility Downs Lodging Credit Facility	Jul. 16, 2012 Downs Lodging, LLC Credit Facility Downs Lodging Credit Facility
Debt Instrument [Line Items]
Credit facility outstanding			$ 400,000,000.0																$ 0							$ 0		$ 0
Borrowing capacity																			16,500,000				1,450,000.00				75,000,000.0
Loan face amount																225,000,000.0															45,000,000
Repayment rate, quarterly			1,000,000.0
Debt outstanding	1,680,415,000	1,697,415,000		394,000,000	397,000,000									221,737,000	221,012,000						363,000	1,450,000		45,000,000	45,000,000
Letters of credit issued																										3,400,000
Credit facility remaining borrowing capacity				71,600,000
Basis spread on variable rate				4.50%				2.25%	3.25%	3.50%	4.50%	3.25%	4.50%	7.50%			6.50%	7.50%
Variable rate basis floor													1.00%					1.50%
Fee assessed on unused revolving credit				0.50%		0.25%	0.50%
Accrued interest including commitment fees				217,000	211,000
Issued at percent of par																98.00%
Initial yield per annum																9.60%
Accrued interest	24,395,000	46,362,000												1,100,000	1,200,000				0	0	370,000	249,000							375,000	375,000
Quarterly amortization of principal																					$ 362,500
Interest rate																							15.00%									13.00%
Interest due monthly																																10.00%
Interest due at maturity																																3.00%
Exit fee																																3.00%