CONSOLIDATED STATEMENTS OF CHANGES IN CAPITAL - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total capital at beginning of period	$ 362,652	$ 168,041	$ 124,827
Net income (loss)	76,417	133,077	92,139
Foreign currency translation adjustment	(8,446)	10,495	0
Contributions from members		97,892	1,075
Share-based compensation	7,569	6,147
Distributions to Mohegan Tribe	(60,000)	(53,000)	(50,000)
Distributions from Salishan-Mohegan, LLC to Mohegan Tribe	(512)
Redemption of membership interest	(68,511)
Total capital at end of period	309,169	362,652	168,041
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total capital at beginning of period	249,102	169,452	125,058
Net income (loss)	75,445	132,650	94,394
Distributions to Mohegan Tribe	(60,000)	(53,000)	(50,000)
Distributions from Salishan-Mohegan, LLC to Mohegan Tribe	(512)
Redemption of membership interest	(67,390)
Total capital at end of period	196,645	249,102	169,452
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total capital at beginning of period	5,106	0	0
Net income (loss)	0	0	0
Foreign currency translation adjustment	(3,981)	5,106
Distributions to Mohegan Tribe		0	0
Redemption of membership interest	0
Total capital at end of period	1,125	5,106	0
Mohegan Tribal Gaming Authority Total Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total capital at beginning of period	254,208	169,452	125,058
Net income (loss)	75,445	132,650	94,394
Foreign currency translation adjustment	(3,981)	5,106
Distributions to Mohegan Tribe	(60,000)	(53,000)	(50,000)
Distributions from Salishan-Mohegan, LLC to Mohegan Tribe	(512)
Redemption of membership interest	(67,390)
Total capital at end of period	197,770	254,208	169,452
Non-controlling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total capital at beginning of period	108,444	(1,411)	(231)
Net income (loss)	972	427	(2,255)
Foreign currency translation adjustment	(4,465)	5,389
Contributions from members		97,892	1,075
Share-based compensation	7,569	6,147
Distributions to Mohegan Tribe		0	0
Redemption of membership interest	(1,121)
Total capital at end of period	$ 111,399	$ 108,444	$ (1,411)