Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock	Exchangeable Shares	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Total
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
Increase (Decrease) in Stockholders' Equity
Net income				24,820		24,820
Exercise of Exchangeable Shares	$ 11	$ (29,639)	29,628
Exercise of Exchangeable Shares (in shares)	1,129
Foreign currency translation loss					11,860	11,860
Change in other comprehensive income (loss), net of tax					(6,065)	(6,065)
Equity-based compensation			1,349			1,349
Exercise of stock options			133			133
Exercise of stock options (in shares)	9
Issuance of common stock pursuant to employee stock purchase plan	$ 1		1,021			1,022
Issuance of common stock pursuant to employee stock purchase plan (in shares)	76
Balance at Jul. 31, 2019	$ 416		512,244	170,414	(20,779)	662,295
Balance (in shares) at Jul. 31, 2019	41,589
Balance at Apr. 30, 2020	$ 426		529,662	168,975	(65,082)	$ 633,981
Balance (in shares) at Apr. 30, 2020	42,554					42,554
Increase (Decrease) in Stockholders' Equity
Net income				27,219		$ 27,219
Foreign currency translation loss					16,281	16,281
Change in other comprehensive income (loss), net of tax					959	959
Equity-based compensation			1,575			1,575
Tax withholding related to net share settlements of stock options/equity awards			(105)			(105)
Exercise of stock options			691			691
Exercise of stock options (in shares)	54
Vesting of restricted stock units (in shares)	7
Issuance of common stock pursuant to employee stock purchase plan	$ 1		1,269			1,270
Issuance of common stock pursuant to employee stock purchase plan (in shares)	58
Balance at Jul. 31, 2020	$ 427		$ 533,092	$ 196,194	$ (47,842)	$ 681,871
Balance (in shares) at Jul. 31, 2020	42,673					42,673