Basis of Presentation, Business and Summary of Significant Accounting Policies - Treasury Stock and Diluted Shares (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015
Treasury Stock
Shares repurchased, cost	$ 5,827
Proceeds from reissuance of treasury stock	4,856
Decrease to Retained earnings (accumulated deficit) for difference between cost of treasury stock and proceeds from reissuance	$ 971
Potentially dilutive shares
Anti-dilutive shares		10,417
Treasury Stock
Treasury Stock
Number of shares repurchased	394,577
Shares repurchased, cost	$ 5,827
Shares reissued	394,577