SEGMENT REPORTING (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment									5
Number of reportable segments | segment									3
Total revenue	$ 130,419	$ 129,309	$ 143,218	$ 120,631	$ 111,422	$ 110,494	$ 110,815	$ 104,806	$ 523,577	$ 437,537	$ 421,053
Income (loss) from operations	29,022	21,451	33,846	30,307	34,697	29,651	31,424	24,877	114,626	120,649	123,723
Income (loss) before provision for income taxes	17,785	$ 10,801	$ 23,325	$ 23,269	27,976	$ 24,287	$ 26,356	$ 19,178	75,180	97,797	101,108
Depreciation and amortization									32,392	22,332	22,204
Interest expense									39,830	23,025	22,809
Capital expenditures, including Tiverton Casino Hotel and new hotel at Twin River Casino									28,237	128,890	47,853
Goodwill	133,082				132,035				133,082	132,035
Total assets	1,021,887				782,352				1,021,887	782,352
Rhode Island
Segment Reporting Information [Line Items]
Total revenue									306,306	302,652	287,859
Income (loss) from operations									102,080	106,055	122,791
Income (loss) before provision for income taxes									97,777	97,508	113,936
Depreciation and amortization									18,473	12,896	11,911
Interest expense									3,274	8,555	8,857
Capital expenditures, including Tiverton Casino Hotel and new hotel at Twin River Casino									16,649	98,700	8,285
Goodwill	83,101				83,101				83,101	83,101
Total assets	537,168				535,795				537,168	535,795
Delaware
Segment Reporting Information [Line Items]
Total revenue									80,806
Income (loss) from operations									9,039
Income (loss) before provision for income taxes									8,934
Depreciation and amortization									3,996
Interest expense									147
Capital expenditures, including Tiverton Casino Hotel and new hotel at Twin River Casino									3,984
Goodwill	1,047				0				1,047	0
Total assets	144,376								144,376
Biloxi
Segment Reporting Information [Line Items]
Total revenue									127,432	125,137	122,694
Income (loss) from operations									23,242	23,475	21,334
Income (loss) before provision for income taxes									23,273	23,479	21,330
Depreciation and amortization									9,743	9,255	10,146
Interest expense									0	13	17
Capital expenditures, including Tiverton Casino Hotel and new hotel at Twin River Casino									6,355	6,315	5,124
Goodwill	48,934				48,934				48,934	48,934
Total assets	259,970				245,376				259,970	245,376
Other
Segment Reporting Information [Line Items]
Total revenue									9,033	9,748	10,500
Income (loss) from operations									(19,735)	(8,881)	(20,402)
Income (loss) before provision for income taxes									(54,804)	(23,190)	(34,158)
Depreciation and amortization									180	181	147
Interest expense									36,409	14,457	13,935
Capital expenditures, including Tiverton Casino Hotel and new hotel at Twin River Casino									1,249	23,875	$ 34,444
Goodwill	0				0				0	0
Total assets	$ 80,373				$ 1,181				$ 80,373	$ 1,181