Consolidated Statements of Stockholders’ Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Exchangeable Shares	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Apr. 30, 2016	$ 329		$ 334,244	$ (22,265)	$ (1,148)	$ 311,160
Balance (in shares) at Apr. 30, 2016	32,893
Increase (Decrease) in Stockholders' Equity
Net income				48,886		48,886
Change in other comprehensive income, net of tax					264	264
Equity-based compensation			2,370			2,370
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, net of underwriting discounts and offering costs (in shares)	8,050
Exercise of stock options	$ 1		513			514
Exercise of stock options (in shares)	28
Balance at Apr. 30, 2017	$ 410		488,459	26,621	(884)	514,606
Balance (in shares) at Apr. 30, 2017	40,971
Increase (Decrease) in Stockholders' Equity
Net income				62,971		62,971
Change in other comprehensive income, net of tax					1,325	1,325
Equity-based compensation			1,513			1,513
Tax withholding related to net share settlements of equity awards			(1,441)			(1,441)
Exercise of stock options	$ 1		476			477
Exercise of stock options (in shares)	98
Balance at Apr. 30, 2018	$ 411		489,007	89,592	441	$ 579,451
Balance (in shares) at Apr. 30, 2018	41,069					41,069
Increase (Decrease) in Stockholders' Equity
Net income				56,002		$ 56,002
Issuance of Exchangeable Shares		$ 29,639				29,639
Repurchase and retirement of common stock	$ (10)		(16,510)			(16,520)
Repurchase and retirement of common stock (in shares)	(978)
Foreign currency translation loss					(22,320)	(22,320)
Change in other comprehensive income, net of tax					(4,695)	(4,695)
Equity-based compensation			3,726			3,726
Tax withholding related to net share settlements of equity awards			(50)			(50)
Exercise of stock options	$ 2		2,536			2,538
Exercise of stock options (in shares)	205
Vesting of restricted stock units (in shares)	5
Issuance of common stock pursuant to employee stock purchase plan	$ 1		1,404			1,405
Issuance of common stock pursuant to employee stock purchase plan (in shares)	74
Balance at Apr. 30, 2019	$ 404	$ 29,639	$ 480,113	$ 145,594	$ (26,574)	$ 629,176
Balance (in shares) at Apr. 30, 2019	40,375					40,375