CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (318,634)	$ (294,486)	$ 162,664
Other comprehensive loss, net of taxes of $0 for 2016, $0 for 2015 and $0 for 2014:
Foreign currency translation adjustment	2,959	(10,556)	(7,613)
Total comprehensive income (loss)	$ (315,675)	$ (305,042)	$ 155,051