Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Comprehensive Income (Loss)
Net income (loss)	$ (51,802)	$ 10,223	$ 50,921
Unrealized gain (loss) on available-for-sale securities	22	(180)
Comprehensive income (loss)	$ (51,780)	$ 10,043	$ 50,921