Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (14,130)	$ (14,819)	$ (32,201)	$ (29,938)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities, net of tax	(11)	52	(1)	27
Comprehensive loss	$ (14,141)	$ (14,767)	$ (32,202)	$ (29,911)