Segment Reporting (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	4
Revenues:
Net revenues	$ 1,590,511	$ 1,228,833	$ 1,114,962
Income (Loss) from Operations
Income (loss) from operations	246,234	184,457	(33,217)
Capital Expenditures Incurred
Capital expenditures incurred	308,934	140,197	176,674
ASSETS
Total assets	3,048,917	2,729,877
Operating segments | Mohegan Sun
Revenues:
Revenues	940,282	816,376	715,674
Income (Loss) from Operations
Income (loss) from operations	213,654	202,311	128,449
Capital Expenditures Incurred
Capital expenditures incurred	29,353	23,250	17,600
ASSETS
Total assets	1,226,689	1,267,538
Operating segments | Mohegan Pennsylvania
Revenues:
Revenues	257,840	221,479	181,160
Income (Loss) from Operations
Income (loss) from operations	43,956	32,534	(115,073)
Capital Expenditures Incurred
Capital expenditures incurred	11,316	6,063	3,559
ASSETS
Total assets	405,455	408,187
Operating segments | Niagara Resorts
Revenues:
Revenues	279,263	99,202	180,025
Income (Loss) from Operations
Income (loss) from operations	38,892	(22,638)	(24,676)
Capital Expenditures Incurred
Capital expenditures incurred	17,232	14,079	17,799
ASSETS
Total assets	474,281	561,812
Operating segments | Management, development and other
Revenues:
Revenues	62,221	70,009	37,189
Income (Loss) from Operations
Income (loss) from operations	(15,948)	17,162	1,585
Capital Expenditures Incurred
Capital expenditures incurred	249,569	7,773	137,171
ASSETS
Total assets	869,117	407,831
Operating segments | All other
Revenues:
Revenues	54,619	18,780	0
Income (Loss) from Operations
Income (loss) from operations	7,158	(1,534)	0
Capital Expenditures Incurred
Capital expenditures incurred	49	88,725	0
ASSETS
Total assets	98,947	98,945
Corporate
Revenues:
Revenues	575	3,247	741
Income (Loss) from Operations
Income (loss) from operations	(41,538)	(43,358)	(23,439)
Capital Expenditures Incurred
Capital expenditures incurred	1,415	307	545
ASSETS
Total assets	1,010,984	996,040
Inter-segment
Revenues:
Revenues	(4,289)	(260)	173
Income (Loss) from Operations
Income (loss) from operations	60	(20)	$ (63)
ASSETS
Total assets	$ (1,036,556)	$ (1,010,476)