Condensed Consolidated Statements of Comprehensive Loss (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (115,896)	$ (144,385)	$ (205,052)	$ (229,102)
Other comprehensive income (loss), net of tax effects:
Foreign currency translation adjustment	504	(417)	1,074	(1,076)
Total other comprehensive income (loss)	504	(417)	1,074	(1,076)
Comprehensive (loss) income	$ (115,392)	$ (144,802)	$ (203,978)	$ (230,178)