Selected Financial Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	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, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 88,160	$ 90,759	$ 92,837	$ 77,789	$ 76,751	$ 84,784	$ 83,967	$ 61,806	$ 349,545	$ 307,308	$ 233,496
Total operating expenses	82,773	77,503	73,763	69,530	67,288	70,086	69,153	57,031	303,569	263,558	214,086
Operating income	5,387	13,256	19,074	8,259	9,463	14,698	14,814	4,775	45,976	43,750	19,410
Net income (loss)	(6,108)	(7,282)	9,124	(425)	(925)	4,389	4,525	(4,451)	(4,691)	3,538	(17,928)
Net income (loss) attributable to the Company	(6,390)	(6,840)	6,724	(206)	$ (2,052)	$ 3,372	$ 3,497	$ (2,878)	(6,712)	1,939	(11,782)
Net income (loss) attributable to common stockholders	$ (7,283)	$ (7,735)	$ 6,526	$ (206)					$ (8,698)	$ 1,939	$ (11,782)
Diluted income (loss) attributable to common stockholders per share (in dollars per share)	$ (0.26)	$ (0.29)	$ 0.27	$ (0.01)	$ (0.08)	$ 0.13	$ 0.14	$ (0.13)	$ (0.34)	$ 0.07	$ (0.73)
Weighted average diluted common shares (in shares)	28,331	27,162	24,773	24,070	24,954	34,429	34,396	22,308	25,888	33,325	16,045