CONSOLIDATED STATEMENTS OF CHANGES IN CAPITAL - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Oct. 01, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total capital at beginning of period	$ 270,794	$ 309,169	$ 362,652
Cumulative-effect adjustment for the adoption of ASC 606 Revenue from Contracts with Customers				$ (41,575)
Net income (loss)	(2,376)	131,608	76,417
Foreign currency translation adjustment	(18,666)	9,362	(8,446)
Distributions to Mohegan Tribe	(60,000)	(60,000)	(60,000)
Redemption of membership interest in the Cowlitz Project	(10,000)		(68,511)
Ownership rights settlement related to Project Inspire		(6,147)	7,569
Redemption of membership interest in Project Inspire		(106,702)
Redemption of membership interest related to the New England Black Wolves franchise	75
Other	31	0	0
Total capital at end of period	137,433	270,794	309,169
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total capital at beginning of period	250,707	196,645	249,102
Cumulative-effect adjustment for the adoption of ASC 606 Revenue from Contracts with Customers				(41,575)
Net income (loss)	(2,545)	130,554	75,445
Distributions to Mohegan Tribe	(60,000)	(60,000)	(60,000)
Redemption of membership interest in the Cowlitz Project	(4,114)		(67,390)
Redemption of membership interest in Project Inspire		(9,996)
Redemption of membership interest related to the New England Black Wolves franchise	(4,499)
Total capital at end of period	137,124	250,707	196,645
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total capital at beginning of period	11,062	1,125	5,106
Foreign currency translation adjustment	(17,726)	1,988	(3,981)
Ownership rights settlement related to Project Inspire		271
Redemption of membership interest in Project Inspire		7,678
Other	31
Total capital at end of period	(6,633)	11,062	1,125
Total Capital Attributable to Mohegan Tribal Gaming Authority
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total capital at beginning of period	261,769	197,770	254,208
Cumulative-effect adjustment for the adoption of ASC 606 Revenue from Contracts with Customers				$ (41,575)
Net income (loss)	(2,545)	130,554	75,445
Foreign currency translation adjustment	(17,726)	1,988	(3,981)
Distributions to Mohegan Tribe	(60,000)	(60,000)	(60,000)
Redemption of membership interest in the Cowlitz Project	(4,114)		(67,390)
Ownership rights settlement related to Project Inspire		271
Redemption of membership interest in Project Inspire		(2,318)
Redemption of membership interest related to the New England Black Wolves franchise	(4,499)
Other	31
Total capital at end of period	130,491	261,769	197,770
Non-controlling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total capital at beginning of period	9,025	111,399	108,444
Net income (loss)	169	1,054	972
Foreign currency translation adjustment	(940)	7,374	(4,465)
Redemption of membership interest in the Cowlitz Project	(5,886)		(1,121)
Ownership rights settlement related to Project Inspire		(6,418)	7,569
Redemption of membership interest in Project Inspire		(104,384)
Redemption of membership interest related to the New England Black Wolves franchise	4,574
Total capital at end of period	6,942	9,025	111,399
Mohegan Tribe
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions from Cowlitz Project	(730)	(6,496)	(512)
Mohegan Tribe \| Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions from Cowlitz Project	(730)	(6,496)	(512)
Mohegan Tribe \| Total Capital Attributable to Mohegan Tribal Gaming Authority
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions from Cowlitz Project	(730)	$ (6,496)	$ (512)
Salishan Company, LLC
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions from Cowlitz Project	(120)
Salishan Company, LLC \| Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions from Cowlitz Project	(120)
Salishan Company, LLC \| Total Capital Attributable to Mohegan Tribal Gaming Authority
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions from Cowlitz Project	$ (120)

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