Condensed Consolidated Statement of Changes in Stockholders' Equity (USD $) In Thousands	Total USD ($)	Common Stock USD ($)	Treasury Stock	Additional Paid-in Capital USD ($)	Accumulated Other Comprehensive Loss USD ($)	Retained Earnings USD ($)
Beginning balance at Apr. 30, 2013	$ 241,349	$ 7		$ 370,397	$ (146)	$ (128,909)
Beginning balance, Shares at Apr. 30, 2013		73,925	(250)
Excess tax benefit related to stock-based expense	90			90
Stock-based expense	4,008			4,008
Exercise of stock options and vested restricted stock units	1,984	725		1,984
Change in foreign currency translation adjustment	(61)				(61)
Change in unrealized loss on investments	(48)				(48)
Net loss	(17,368)					(17,368)
Ending balance at Jul. 31, 2013	$ 229,954	$ 7		$ 376,479	$ (255)	$ (146,277)
Ending balance, Shares at Jul. 31, 2013		74,650	(250)