MOHEGAN VENTURES-NORTHWEST, LLC (COWLITZ PROJECT) - Reconciliation of the Redemption Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Redemption Liability [Roll Forward]
Balance, September 30, 2017	$ 72,351
Accretion of discount to the Redemption Liability	1,733	$ 0
Conversion to Redemption Note Payable	(74,084)
Balance, December 31, 2017	0
Movement In Redemption Notes Payable [Roll Forward]
Balance, September 30, 2017	0
Initial Redemption Note Payable	74,084
Amortization of discount to the Redemption Note Payable	407
Balance, December 31, 2017	$ 74,491