Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Data Unaudited
Revenues	$ 227,379	$ 266,256	$ 255,010	$ 234,551	$ 203,840	$ 199,536	$ 198,356	$ 182,809	$ 179,936	$ 90,528	$ 72,725	$ 67,083	$ 983,196	$ 784,541	$ 410,272
Less-promotional allowances	(20,929)	(24,691)	(23,695)	(20,985)	(17,680)	(15,996)	(15,723)	(15,358)	(15,841)	(11,579)	(10,976)	(10,053)	(90,300)	(64,757)	(48,449)
Net operating revenues	206,450	241,565	231,315	213,566	186,160	183,540	182,633	167,451	164,095	78,949	61,749	57,030	892,896	719,784	361,823
Operating expenses	189,405	208,731	200,768	194,854	171,464	161,610	160,430	154,766	156,755	72,943	56,054	53,726	793,758	648,270	339,478
Operating income	13,091	28,109	29,655	18,263	13,281	24,092	23,059	12,084	6,450	2,778	6,775	1,552	89,118	72,516	17,555
Net (loss) income	$ 959	$ 9,682	$ 10,791	$ 3,370	$ 110,153	$ 5,399	$ 4,795	$ (6,164)	$ (10,834)	$ (4,064)	$ 2,909	$ (2,333)	$ 24,802	$ 114,183	$ (14,425)
Earnings Per Share, Basic [Abstract]
Basic net (loss) income per common share	$ 0.02	$ 0.21	$ 0.23	$ 0.07	$ 2.36	$ 0.12	$ 0.10	$ (0.13)
Weighted Average Basic Shares Outstanding	47,105,744	47,193,120	47,071,608	46,933,094	46,670,735	46,516,614	46,516,614	46,494,638					47,033,311	46,550,042	29,901,405
Earnings Per Share, Diluted [Abstract]
Diluted net income (loss) per common share	$ 0.02	$ 0.20	$ 0.23	$ 0.07	$ 2.33	$ 0.12	$ 0.10	$ (0.13)					$ 0.52	$ 2.43	$ (0.48)
Weighted Average Diluted Shares Outstanding	47,849,554	47,834,644	47,721,075	47,534,761	47,227,127	46,763,589	46,657,618	46,494,638					47,701,562	47,008,980	29,901,405
Basic and diluted net (loss) income per common share									$ (0.23)	$ (0.16)	$ 0.12	$ (0.10)
Weighted average shares outstanding—basic and diluted									46,441,249	26,075,022	23,311,492	23,311,492