CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (53,787)	$ (52,676)
Other comprehensive (loss) income :
Net unrealized loss on marketable securities	(3,986)	0
Cumulative translation adjustment, net of tax of $0	(32)	236
Defined benefit pension obligation, net of tax of $0	55	77
Other comprehensive (loss) income	(3,963)	313
Comprehensive loss	$ (57,750)	$ (52,363)