CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (26,994)	$ (27,171)
Other comprehensive gain, before tax:
Net change in unrealized gain on available-for-sale investments	119	129
Foreign currency translation gain	576	733
Net change in unrealized loss on derivative instruments	1,526	2,610
Other comprehensive gain, before tax	2,221	3,472
Tax effect	(816)	0
Other comprehensive gain, net of tax	1,405	3,472
Comprehensive loss	$ (25,589)	$ (23,699)