REVENUE RECOGNITION - Impact of Adoption on Income Statement (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Gross revenues	$ 64,359	$ 75,423	$ 180,536	$ 210,844
Less promotional allowances		(12,396)		(36,174)
Net revenues	64,359	63,027	180,536	174,670
Operating expenses:
Selling, general and administrative	16,793	16,398	48,130	46,117
Depreciation and amortization	3,651	3,722	11,081	11,397
Loss on disposition of assets	8		12	4
Total operating expenses	50,493	49,777	146,771	142,141
Net income	$ 10,859	$ 9,030	$ 26,839	$ 21,141
Basic (in dollars per share)	$ 0.61	$ 0.51	$ 1.51	$ 1.20
Diluted (in dollars per share)	$ 0.58	$ 0.49	$ 1.44	$ 1.16
Casino
Revenues:
Gross revenues	$ 33,504	$ 48,574	$ 94,591	$ 135,207
Operating expenses:
Operating expenses	11,455	19,097	33,007	54,837
Food and beverage
Revenues:
Gross revenues	18,472	16,342	52,951	47,394
Operating expenses:
Operating expenses	13,700	6,699	39,990	19,461
Hotel
Revenues:
Gross revenues	9,167	7,316	23,627	19,204
Operating expenses:
Operating expenses	3,315	2,735	9,870	7,192
Other
Revenues:
Gross revenues	3,216	3,191	9,367	9,039
Operating expenses:
Operating expenses	1,571	$ 1,126	4,681	$ 3,133
ASC 606 Changes
Revenues:
Gross revenues	12,903		36,780
Less promotional allowances	(12,938)		(37,131)
Net revenues	(35)		(351)
Operating expenses:
Total operating expenses	(35)		(351)
ASC 606 Changes | Casino
Revenues:
Gross revenues	15,755		44,341
Operating expenses:
Operating expenses	8,521		24,852
ASC 606 Changes | Food and beverage
Revenues:
Gross revenues	(1,412)		(4,228)
Operating expenses:
Operating expenses	(7,271)		(21,138)
ASC 606 Changes | Hotel
Revenues:
Gross revenues	(1,477)		(3,414)
Operating expenses:
Operating expenses	(748)		(2,481)
ASC 606 Changes | Other
Revenues:
Gross revenues	37		81
Operating expenses:
Operating expenses	(537)		(1,584)
Pre ASC 606 Adoption
Revenues:
Gross revenues	77,262		217,316
Less promotional allowances	(12,938)		(37,131)
Net revenues	64,324		180,185
Operating expenses:
Selling, general and administrative	16,793		48,130
Depreciation and amortization	3,651		11,081
Loss on disposition of assets	8		12
Total operating expenses	50,458		146,420
Net income	$ 10,859		$ 26,839
Basic (in dollars per share)	$ 0.61		$ 1.51
Diluted (in dollars per share)	$ 0.58		$ 1.44
Pre ASC 606 Adoption | Casino
Revenues:
Gross revenues	$ 49,259		$ 138,932
Operating expenses:
Operating expenses	19,976		57,859
Pre ASC 606 Adoption | Food and beverage
Revenues:
Gross revenues	17,060		48,723
Operating expenses:
Operating expenses	6,429		18,852
Pre ASC 606 Adoption | Hotel
Revenues:
Gross revenues	7,690		20,213
Operating expenses:
Operating expenses	2,567		7,389
Pre ASC 606 Adoption | Other
Revenues:
Gross revenues	3,253		9,448
Operating expenses:
Operating expenses	$ 1,034		$ 3,097