Condensed Consolidated Statements of Comprehensive Loss (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Net loss	$ (14,154)	$ (11,242)	$ (31,522)	$ (29,781)
Other comprehensive income, net of tax and reclassification adjustments:
Foreign currency translation adjustment	194	60	133	(9)
Unrealized gains on investments	94	46	46	23
Total other comprehensive income, net of tax	288	106	179	14
Comprehensive loss	$ (13,866)	$ (11,136)	$ (31,343)	$ (29,767)