Condensed Consolidated Statements of Comprehensive Loss (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2013
Net loss	$ (7,963)	$ (10,827)	$ (39,485)	$ (40,608)
Other comprehensive income (loss), net of tax and reclassification adjustments:
Foreign currency translation adjustment	136	(21)	269	(30)
Unrealized gains (losses) on investments	44	(6)	90	17
Total other comprehensive income (loss), net of tax	180	(27)	359	(13)
Comprehensive loss	$ (7,783)	$ (10,854)	$ (39,126)	$ (40,621)