BASIS OF PRESENTATION - Long-Term Receivables (Details) (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2015		Mar. 31, 2015		Dec. 31, 2014	Sep. 30, 2014
Notes, Loans and Financing Receivable, Gross, Noncurrent [Roll Forward]
Balance, beginning of period	$ 71,643,000	[1]	$ 69,208,000	[1]
Additions: Issuance of affiliate advances and other loans, including interest receivable	2,602,000		5,075,000
Additions: Cowlitz Project land transfer	19,951,000	[2]	19,951,000	[2]
Deductions: Payments received	(39,000)		(77,000)
Balance, end of period	94,157,000	[1]	94,157,000	[1]
Interest receivable	39,300,000		39,300,000		37,500,000	35,700,000
Affiliates
Notes, Loans and Financing Receivable, Gross, Noncurrent [Roll Forward]
Balance, beginning of period	69,048,000	[1]	66,596,000	[1]
Additions: Issuance of affiliate advances and other loans, including interest receivable	2,568,000		5,020,000
Additions: Cowlitz Project land transfer	19,951,000	[2]	19,951,000	[2]
Deductions: Payments received	0		0
Balance, end of period	91,567,000	[1]	91,567,000	[1]
Tenants and Others
Notes, Loans and Financing Receivable, Gross, Noncurrent [Roll Forward]
Balance, beginning of period	2,595,000	[1]	2,612,000	[1]
Additions: Issuance of affiliate advances and other loans, including interest receivable	34,000		55,000
Additions: Cowlitz Project land transfer	0	[2]	0	[2]
Deductions: Payments received	(39,000)		(77,000)
Balance, end of period	$ 2,590,000	[1]	$ 2,590,000	[1]

[1] Includes interest receivable of $39.3 million, $37.5 million and $35.7 million as of March 31, 2015, December 31, 2014 and September 30, 2014, respectively. The WTG receivables no longer accrue interest pursuant to a release and reimbursement agreement entered into in September 2010.

[2] Relates to the transfer of land for the proposed Cowlitz Project site between Salishan-Mohegan and the Cowlitz Tribe (refer to Note 7).