Basis of Presentation, Business and Summary of Significant Accounting Policies - Treasury Stock (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jul. 31, 2015	Apr. 30, 2016
Treasury Stock
Shares repurchased, cost		$ 5,827
Proceeds from reissuance		6,518
Increase to Accumulated deficit for difference between cost of treasury stock and proceeds from reissuance		$ 442
Treasury Stock
Treasury Stock
Number of shares repurchased		394,577
Shares repurchased, cost		$ 5,827
Shares reissued	179,675	394,577
Proceeds from reissuance	$ 2,211	$ 5,827