CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net loss	$ (41,140)	$ (187,083)
Other comprehensive income (loss):
Foreign currency translation	35	(7)
Unrealized loss on marketable securities, net of tax	(505)	(34)
Unrealized gain on long term investment, net of tax (Note 2)		8,258
Defined benefit pension obligations, net of tax	111	46
Other comprehensive income (loss)	(359)	8,263
Comprehensive loss	$ (41,499)	$ (178,820)