Equity Incentive Plans - Summary of RSA Activity (Details)	12 Months Ended
	Apr. 30, 2019 $ / shares shares
Non-option Awards, Outstanding Number [Roll Forward]
Number of Awards Outstanding at Year End (in shares)	0
RSAs | 2012 Plan
Non-option Awards, Outstanding Number [Roll Forward]
Number of Awards Outstanding at Beginning of Year (in shares)	244,498
Number of Awards, RSAs subscribed (in shares)	(244,498)
Non-option Awards, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted-Average Grant Date Fair Value, Outstanding (in dollar per share) | $ / shares	$ 11.46
Weighted-Average Grant Date Fair Value, RSAs subscribed (in dollar per share) | $ / shares	$ 11.46