Equity-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Other disclosures
Equity-based compensation	$ 7,060	$ 3,906	$ 1,695
Selling, general and administrative expenses
Other disclosures
Equity-based compensation	$ 6,500	$ 3,600	1,700
Stock Options
Number of Options
Outstanding, beginning of the period (in shares)	2,080
Options granted (in shares)	386
Options exercised (in shares)	(874)
Options forfeited (in shares)	(105)
Outstanding, end of the period (in shares)	1,487	2,080
Exercisable at end of period (in shares)	941
Vested and expected to vest at end of period (in shares)	1,481
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 16.34
Options granted (in dollars per share)	21.63
Options exercised (in dollars per share)	13.22
Options forfeited (in dollars per share)	25.73
Outstanding, end of the period (in dollars per share)	18.85	$ 16.34
Exercisable at end of period (in dollars per share)	16.32
Vested and expected to vest at end of period (in dollars per share)	$ 18.83
Other disclosures
Weighted Average Remaining Contractual Life, Outstanding (in years)	6 years 4 months 24 days	6 years 1 month 24 days
Weighted Average Remaining Contractual Life, Exercisable at end of period (in years)	4 years 11 months 23 days
Weighted Average Remaining Contractual Life, Vested and expected to vest at end of period (in years)	6 years 4 months 20 days
Aggregate Intrinsic Value, Outstanding	$ 3,895	$ 7,615
Aggregate Intrinsic Value, Exercisable at end of period	3,866
Aggregate Intrinsic Value, Vested and expected to vest at end of period	3,895
Intrinsic value of options exercised	11,500	$ 1,600	$ 4,300
Unrecognized compensation cost	$ 3,600
Weighted-average period for recognition of unrecognized compensation expense (in years)	1 year 10 months 24 days