ACQUISITIONS - Additional Information (Details) $ in Thousands				12 Months Ended
	Jul. 10, 2019 USD ($)	Mar. 28, 2019 USD ($) shares	Jan. 29, 2019 USD ($) casino	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2019 USD ($)
Business Acquisition [Line Items]
Total consideration paid, net of cash acquired				$ 9,606	$ 0	$ 0
Transaction costs				10,900	6,844
Goodwill				133,082	132,035
Dover Downs
Business Acquisition [Line Items]
Percentage of common stock owned by acquiree		7.225%
Common stock issued (in shares) | shares		2,976,825
Total consideration paid		$ 115,886
Total consideration paid, net of cash acquired		96,400
Cash acquired		19,500
Transaction costs				7,883	6,636
Goodwill				1,047			$ 0
Rated player relationships				5,110			$ 5,110
Net revenue from date of acquisition				80,800
Net income from date of acquisition				6,000
Dover Downs | Trademarks
Business Acquisition [Line Items]
Rated player relationships		$ 3,900
Acquired intangible assets, useful life		10 years
Dover Downs | Rated player relationships
Business Acquisition [Line Items]
Rated player relationships		$ 800
Acquired intangible assets, useful life		8 years
Dover Downs | Hotel and Conference Pre-bookings
Business Acquisition [Line Items]
Rated player relationships		$ 400
Acquired intangible assets, useful life		3 years
Black Hawk
Business Acquisition [Line Items]
Total consideration paid, net of cash acquired			$ 53,000
Transaction costs				1,700	200
Goodwill			4,400
Rated player relationships			$ 6,000
Number of businesses acquired | casino			3
Isle Kansas City and Lady Luck Vicksburg
Business Acquisition [Line Items]
Total consideration paid	$ 230,000
Transaction costs				$ 1,293	$ 0