Stockholders Equity - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015
Number of Options
Outstanding beginning of the period (in shares)	5,093	7,091
Options granted (in shares)	2,947	939
Options exercises (in shares)	(227)	(1,246)
Options forfeited (in shares)	(484)	(877)
Options expired (in shares)	(641)	(814)
Outstanding end of the period (in shares)	6,688	5,093
Options vested and expected to vest (in shares)	6,666
Options vested and exercisable (in shares)	3,004
Weighted Average Exercise Price
Outstanding beginning balance	$ 7.83	$ 7.74
Options Granted	4.83	7.31
Options exercised	3.95	4.18
Options forfeited	7.42	8.98
Options expired	8.14	10.78
Outstanding ending balance	6.64	$ 7.83
Options vested and expected to vest, weighted average exercise price	6.64
Options vested and exercisable, weighted average exercise price	$ 8.04
Weighted average contractual term	6 years 5 months 6 days	7 years
Options vested and expected to vest, weighted average remaining contractual term	6 years 5 months 6 days
Options vested and exercisable, weighted average remaining contractual term	4 years 7 months
Aggregate intrinsic value	$ 591	$ 1,590
Options vested and expected to vest, aggregate intrinsic value	591
Options vested and exercisable, aggregate intrinsic value	$ 373