CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME/(LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (29,155)	$ (63,077)	$ (75,076)	$ (131,957)
Unrealized gains (losses) on investments, net	(59)	31	149	134
Tax benefit (expense) on unrealized gain / loss on investments, net	23	(12)	(57)	(51)
Other comprehensive income (loss), net of tax	(36)	19	92	83
Comprehensive loss	$ (29,191)	$ (63,058)	$ (74,984)	$ (131,874)