BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Reserves For Doubtful Collection of Long-term Receivables (Details) - Allowance for Notes Receivable $ in Thousands	12 Months Ended
	Sep. 30, 2016 USD ($)
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	$ 31,070
Additions: Charges to bad debt expense	2,465
Deductions: Adjustments	(17,150)	[1]
Balance, end of period	16,385
Salishan-Mohegan
Allowance for Loan and Lease Losses [Roll Forward]
Write-off of receivables	7,300
Affiliates
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	31,028
Additions: Charges to bad debt expense	2,465
Deductions: Adjustments	(17,108)	[1]
Balance, end of period	16,385
Others
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	42
Additions: Charges to bad debt expense	0
Deductions: Adjustments	(42)	[1]
Balance, end of period	0
Wisconsin Tribal Gaming
Allowance for Loan and Lease Losses [Roll Forward]
Write-off of receivables	$ 9,800

[1] Adjustments to reserves for doubtful collection of receivables from affiliates include $7.3 million related to the Salishan-Mohegan receivables and $9.8 million related to the WTG receivables.