Cover - USD ($)	12 Months Ended
	Sep. 30, 2020	Mar. 31, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	033-80655
Entity Registrant Name	MOHEGAN TRIBAL GAMING AUTHORITY
Entity Tax Identification Number	06-1436334
Entity Address, Address Line One	One Mohegan Sun Boulevard
Entity Address, City or Town	Uncasville
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06382
City Area Code	(860)
Local Phone Number	862-8000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	Yes
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	0
Entity Public Float		$ 0
Entity Central Index Key	0001005276
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
No Trading Symbol Flag	true
Amendment Flag	false