Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total
Balance at Apr. 30, 2015	$ 328	$ 329,884	$ (30,650)	$ 10		$ 299,572
Balance (in shares) at Apr. 30, 2015	32,757,905
Increase (Decrease) in Stockholders' Equity
Net income			12,564			12,564
Change in accounting | Change in accounting for liability equity-based awards			(3,208)			(3,208)
Increase in fair value of financial instruments, net of tax				(1,158)		(1,158)
Equity-based compensation		2,699				2,699
Stock repurchases					$ (5,827)	(5,827)
Stock repurchases (in shares)					394,577
Exercise of stock options	$ 1	1,661	(971)		$ 5,827	6,518
Exercise of stock options (in shares)	135,000				(394,577)
Balance at Apr. 30, 2016	$ 329	334,244	(22,265)	(1,148)		311,160
Balance (in shares) at Apr. 30, 2016	32,892,905
Increase (Decrease) in Stockholders' Equity
Net income			26,387			26,387
Increase in fair value of financial instruments, net of tax				12		12
Equity-based compensation		1,283				1,283
Issuance of common stock in initial public offering, net of underwriting discounts and offering costs	$ 80	151,332				151,412
Issuance of common stock in initial public offering (in shares)	8,050,000
Balance at Oct. 31, 2016	$ 409	$ 486,859	$ 4,122	$ (1,136)		$ 490,254
Balance (in shares) at Oct. 31, 2016	40,942,905