Consolidated statements of comprehensive loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (96,412)	$ (63,741)	$ (492,646)	$ (192,358)
Other comprehensive income (loss), net of tax of nil:
Foreign currency translation adjustments	1,741	(9,901)	(600)	(7,535)
Comprehensive loss	$ (94,671)	$ (73,642)	$ (493,246)	$ (199,893)