Equity-Based Compensation - Restricted Stock Units (Details) - Restricted Stock Units $ / shares in Units, shares in Thousands, $ in Millions	6 Months Ended
	Oct. 31, 2018 USD ($) $ / shares shares
Restricted stock units granted to employees (in shares) | shares	166,973
Fair value on grant date (in dollars per share) | $ / shares	$ 25.58
Unrecognized compensation cost | $	$ 4.2
Weighted-average period for recognition of unrecognized compensation expense (in years)	2 years 4 months 24 days
Number of Restricted Stock Units
Outstanding, beginning of the period (in shares) | shares	21,766
Granted (in shares) | shares	166,973
Vested (in shares) | shares	(655)
Forfeited (in shares) | shares	1,229
Outstanding, end of the period (in shares) | shares	186,855
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 37.49
Granted (in dollars per share) | $ / shares	25.58
Vested (in dollars per share) | $ / shares	37.49
Forfeited (in dollars per share) | $ / shares	35.37
Outstanding, end of the period (in dollars per share) | $ / shares	$ 26.86