CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net income (loss)	$ 59,536	$ (18,760)	$ (168,464)
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities, net	3	1,305	(4,001)
Less: realized gain on marketable securities, net	0	(1,220)	0
Add: Reclassification adjustments for other-than temporary impairment loss included in net loss	0	0	3,752
Comprehensive income (loss)	$ 59,539	$ (18,675)	$ (168,713)