CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss) attributable to common stockholders	$ 7,540	$ (17,231)	$ (10,455)	$ (28,952)
Other comprehensive income:
Unrealized gain on derivatives, net of tax expense of $904 for the three months and six months ended June 30, 2015	2,861		1,069
Less reclassification of net loss on derivatives to earnings	(356)		(356)
Comprehensive loss	$ 10,757	$ (17,231)	$ (9,030)	$ (28,952)