Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (273,551)	$ (143,255)	$ (83,440)
Other comprehensive income (loss):
Foreign currency translation adjustment	483	(116)	140
Total other comprehensive income (loss)	483	(116)	140
Comprehensive loss	$ (273,068)	$ (143,371)	$ (83,300)