Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Condensed Consolidated Statement of Comprehensive Loss [Abstract]
Net loss	$ (38,441)	$ (71,050)	$ (47,705)	$ (21,816)	$ (26,390)	$ (59,724)	$ (157,196)	$ (107,930)
Change in cumulative translation adjustment, net of tax	(2,967)	$ (1,916)	$ 1,073	(826)	$ (7,053)	$ 4,388	(3,810)	(3,491)
Comprehensive loss	$ (41,408)			$ (22,642)			$ (161,006)	$ (111,421)