Equity-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Apr. 30, 2020
Other disclosures
Equity-based compensation	$ 1,605	$ 1,395
Selling, general and administrative expenses
Other disclosures
Equity-based compensation	$ 1,400	1,200
Stock Options
Number of Options
Outstanding, beginning of the period (in shares)	1,487
Options granted (in shares)	0
Options exercised (in shares)	(37)
Options forfeited (in shares)	(42)
Outstanding, end of the period (in shares)	1,408		1,487
Exercisable at end of period (in shares)	943
Vested and expected to vest at end of period (in shares)	1,404
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 18.85
Options exercised (in dollars per share)	13.10
Options forfeited (in dollars per share)	24.64
Outstanding, end of the period (in dollars per share)	18.83		$ 18.85
Exercisable at end of period (in dollars per share)	16.58
Vested and expected to vest at end of period (in dollars per share)	$ 18.82
Other disclosures
Weighted Average Remaining Contractual Life, Outstanding (in years)	6 years 1 month 6 days		6 years 4 months 24 days
Weighted Average Remaining Contractual Life, Exercisable at end of period (in years)	4 years 10 months 24 days
Weighted Average Remaining Contractual Life, Vested and expected to vest at end of period (in years)	6 years 1 month 6 days
Aggregate Intrinsic Value, Outstanding	$ 7,825		$ 3,895
Aggregate Intrinsic Value, Exercisable at end of period	7,143
Aggregate Intrinsic Value, Vested and expected to vest at end of period	7,821
Intrinsic value of options exercised	300	$ 100
Unrecognized compensation cost	$ 2,900
Weighted-average period for recognition of unrecognized compensation expense (in years)	1 year 9 months 18 days
Options granted (in shares)	0