Equity-Based Compensation - (Tables)

6 Months Ended

Oct. 31, 2017

Equity-Based Compensation

Summary of stock option activity

				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
	Number of	Exercise		Contractual	Intrinsic
	Options	Price		Life (years)	Value
	(shares and dollars in thousands)
Outstanding as of May 1, 2017	2,088	$	13.49	7.23	$	47,336
Options granted	—		—
Options exercised	161		12.53
Options forfeited	—		—
Options expired	—		—
Outstanding as of October 31, 2017	1,927	$	13.57	6.73	$	39,467
Exercisable as of October 31, 2017	1,501	$	12.83	6.56	$	31,854
Expected to vest after October 31, 2017	426	$	16.17	7.31	$	7,614

Schedule of weighted average assumptions used in Black-Scholes option-pricing model

	October 31, 2016
Volatility	41.10	%
Expected life (years)	6.0
Risk-free interest rate	1.53	%
Dividend yield	—	%