Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Comprehensive Loss
Net income (loss)	$ 686	$ (183,822)	$ (581,252)
Other comprehensive loss, net of tax:
Foreign currency translation adjustment during the period	(3,272)	(1,665)	(1,245)
Change in fair value of corporate debt securities
Unrealized holding losses on corporate debt securities arising during the period			(98)
Less: Reclassification adjustments for gains included in net loss			(1,296)
Change in fair value of corporate debt securities, net			(1,394)
Other comprehensive loss	(3,272)	(1,665)	(2,639)
Comprehensive loss	$ (2,586)	$ (185,487)	$ (583,891)