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)	$ 91,221	$ 13,944	$ (10,925)
Other comprehensive income (loss):
Unrealized net gain (loss) on marketable securities, net of tax	354	(334)	(154)
Other comprehensive income (loss):	354	(334)	(154)
Comprehensive income (loss)	$ 91,575	$ 13,610	$ (11,079)