Segment Reporting (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) segment	Jun. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			4
Net Revenues
Net revenues	$ 417,078	$ 328,189	$ 1,177,517	$ 837,598
Income (Loss) from Operations
Income (loss) from operations	90,126	64,041	182,771	119,507
Capital Expenditures Incurred
Capital expenditures incurred			191,293	122,816
Total Assets
Total assets	3,068,685		3,068,685		$ 2,729,877
Operating segments | Mohegan Sun
Net Revenues
Net revenues	236,465	220,061	703,521	574,974
Income (Loss) from Operations
Income (loss) from operations	58,744	65,183	165,088	144,195
Capital Expenditures Incurred
Capital expenditures incurred			19,253	12,680
Total Assets
Total assets	1,231,731		1,231,731		1,267,538
Operating segments | Mohegan Sun Pocono
Net Revenues
Net revenues	66,783	62,931	193,162	153,392
Income (Loss) from Operations
Income (loss) from operations	11,917	12,319	33,641	20,116
Capital Expenditures Incurred
Capital expenditures incurred			6,750	4,182
Total Assets
Total assets	404,607		404,607		408,187
Operating segments | MGE Niagara Resorts
Net Revenues
Net revenues	79,627	14,380	194,719	41,193
Income (Loss) from Operations
Income (loss) from operations	14,962	(11,755)	24,566	(35,553)
Capital Expenditures Incurred
Capital expenditures incurred			11,176	9,654
Total Assets
Total assets	503,402		503,402		561,812
Operating segments | Management, development and other
Net Revenues
Net revenues	16,817	21,782	46,334	53,691
Income (Loss) from Operations
Income (loss) from operations	8,269	5,711	(16,945)	12,711
Capital Expenditures Incurred
Capital expenditures incurred			154,041	6,974
Total Assets
Total assets	849,062		849,062		407,831
Operating segments | All other
Net Revenues
Net revenues	18,776	8,362	42,231	10,077
Income (Loss) from Operations
Income (loss) from operations	6,798	(1,045)	6,540	(499)
Capital Expenditures Incurred
Capital expenditures incurred			(231)	89,019
Total Assets
Total assets	101,154		101,154		98,945
Corporate
Net Revenues
Net revenues	85	162	471	2,949
Income (Loss) from Operations
Income (loss) from operations	(10,634)	(6,374)	(30,175)	(21,459)
Capital Expenditures Incurred
Capital expenditures incurred			304	307
Total Assets
Total assets	1,008,920		1,008,920		996,040
Inter-segment
Net Revenues
Net revenues	(1,475)	511	(2,921)	1,322
Income (Loss) from Operations
Income (loss) from operations	70	$ 2	56	$ (4)
Total Assets
Total assets	$ (1,030,191)		$ (1,030,191)		$ (1,010,476)