Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013
Stock-based expense	$ 12,802	$ 14,468	$ 22,453
Cost of revenue
Stock-based expense	1,517	1,155	677
Selling and Marketing Expense
Stock-based expense	3,923	4,496	3,033
Research and Development Expense
Stock-based expense	2,561	2,817	2,840
General and Administrative Expense
Stock-based expense	$ 4,677	$ 5,357	$ 4,608