CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
NET LOSS	$ (171,799)	$ (133,969)	$ (176,353)
OTHER COMPREHENSIVE INCOME (LOSS):
Net foreign currency gain (loss)	(59)	(75)	361
Unrealized holding gain (loss) arising during the period, net of tax impact of $1,581, $(2,931) and $(3,535) for the years ended December 31, 2015, 2014 and 2013, respectively.	(2,878)	5,088	6,275
Less reclassifications to net loss, net of tax impact of $(681), $0 and $0 for the years ended December 31, 2015, 2014 and 2013, respectively.	1,192		1
Net change in unrealized holding gains, net of tax	(4,070)	5,088	6,274
Unrealized holding gain (loss) arising during the period, net of tax impact of $0, $(1,214) and $789 for the years ended December 31, 2015, 2014 and 2013, respectively.	17,300	18,078	(1,366)
Less reclassifications to net loss, net of tax impact of $0, $(365) and $(28) for the years ended December 31, 2015, 2014 and 2013, respectively.	19,604	643	49
Net change in unrealized holding gains (loss), net of tax	(2,304)	17,435	(1,415)
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	(6,433)	22,448	5,220
COMPREHENSIVE LOSS	$ (178,232)	$ (111,521)	$ (171,133)