Organization and Basis of Presentation - Revenue Disaggregation by Geographic Location and Revenue Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Net revenues	$ 107,199	$ 347,607	$ 820,952	$ 974,804
Connecticut
Disaggregation of Revenue [Line Items]
Net revenues	78,239	251,045	503,860	742,115
Pennsylvania
Disaggregation of Revenue [Line Items]
Net revenues	10,512	65,393	125,568	187,425
Niagara Falls
Disaggregation of Revenue [Line Items]
Net revenues	11,346	21,288	167,602	21,288
Other
Disaggregation of Revenue [Line Items]
Net revenues	6,756	9,941	24,450	24,156
Gaming
Disaggregation of Revenue [Line Items]
Net revenues	89,379	235,418	569,642	669,172
Gaming | Connecticut
Disaggregation of Revenue [Line Items]
Net revenues	67,966	165,968	352,946	496,281
Gaming | Pennsylvania
Disaggregation of Revenue [Line Items]
Net revenues	10,112	55,199	107,499	158,640
Gaming | Niagara Falls
Disaggregation of Revenue [Line Items]
Net revenues	11,301	14,251	109,197	14,251
Gaming | Other
Disaggregation of Revenue [Line Items]
Net revenues		0		0
Food and beverage
Disaggregation of Revenue [Line Items]
Net revenues	3,009	37,171	91,098	105,485
Food and beverage | Connecticut
Disaggregation of Revenue [Line Items]
Net revenues	2,779	27,941	52,734	85,156
Food and beverage | Pennsylvania
Disaggregation of Revenue [Line Items]
Net revenues	231	5,929	10,899	17,121
Food and beverage | Niagara Falls
Disaggregation of Revenue [Line Items]
Net revenues		3,391	27,544	3,391
Food and beverage | Other
Disaggregation of Revenue [Line Items]
Net revenues	(1)	(90)	(79)	(183)
Hotel
Disaggregation of Revenue [Line Items]
Net revenues	2,589	23,794	50,293	68,776
Hotel | Connecticut
Disaggregation of Revenue [Line Items]
Net revenues	2,568	20,885	40,491	62,094
Hotel | Pennsylvania
Disaggregation of Revenue [Line Items]
Net revenues	21	2,163	3,485	5,938
Hotel | Niagara Falls
Disaggregation of Revenue [Line Items]
Net revenues		747	6,319	747
Hotel | Other
Disaggregation of Revenue [Line Items]
Net revenues		(1)	(2)	(3)
Retail, entertainment and other
Disaggregation of Revenue [Line Items]
Net revenues	12,222	51,224	109,919	131,371
Retail, entertainment and other | Connecticut
Disaggregation of Revenue [Line Items]
Net revenues	4,926	36,251	57,689	98,584
Retail, entertainment and other | Pennsylvania
Disaggregation of Revenue [Line Items]
Net revenues	148	2,102	3,685	5,726
Retail, entertainment and other | Niagara Falls
Disaggregation of Revenue [Line Items]
Net revenues	45	2,899	24,542	2,899
Retail, entertainment and other | Other
Disaggregation of Revenue [Line Items]
Net revenues	211	406	519	1,165
Management and development | Connecticut
Disaggregation of Revenue [Line Items]
Net revenues		0		0
Management and development | Pennsylvania
Disaggregation of Revenue [Line Items]
Net revenues		0		0
Management and development | Niagara Falls
Disaggregation of Revenue [Line Items]
Net revenues		0		0
Management and development | Other
Disaggregation of Revenue [Line Items]
Net revenues	$ 6,546	$ 9,626	$ 24,012	$ 23,177