Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Apr. 30, 2020		42,554
Beginning balance at Apr. 30, 2020	$ 633,981	$ 426	$ 529,662	$ 168,975	$ (65,082)
Increase (Decrease) in Stockholders' Equity
Net income	27,219			27,219
Foreign currency translation adjustments	16,281				16,281
Other comprehensive income, net of tax	959				959
Equity-based compensation	1,575		1,575
Exercise of stock options (in shares)		54
Exercise of stock options	691		691
Vesting of restricted stock units (in shares)		7
Tax withholding related to net share settlements of equity awards	(105)		(105)
Issuance of common stock pursuant to employee stock purchase plan (in shares)		58
Issuance of common stock pursuant to employee stock purchase plan	1,270	$ 1	1,269
Ending balance (in shares) at Jul. 31, 2020		42,673
Ending balance at Jul. 31, 2020	681,871	$ 427	533,092	196,194	(47,842)
Beginning balance (in shares) at Apr. 30, 2020		42,554
Beginning balance at Apr. 30, 2020	633,981	$ 426	529,662	168,975	(65,082)
Increase (Decrease) in Stockholders' Equity
Net income	55,688
Foreign currency translation adjustments	19,440
Other comprehensive income, net of tax	3,803
Ending balance (in shares) at Oct. 31, 2020		42,690
Ending balance at Oct. 31, 2020	717,897	$ 427	534,646	224,663	(41,839)
Beginning balance (in shares) at Jul. 31, 2020		42,673
Beginning balance at Jul. 31, 2020	681,871	$ 427	533,092	196,194	(47,842)
Increase (Decrease) in Stockholders' Equity
Net income	28,469			28,469
Repurchase and retirement of common stock (in shares)		(50)
Repurchase and retirement of common stock	(1,222)	$ (1)	(1,221)
Foreign currency translation adjustments	3,159				3,159
Other comprehensive income, net of tax	2,844				2,844
Equity-based compensation	3,253		3,253
Exercise of stock options (in shares)		5
Exercise of stock options	172		172
Vesting of restricted stock units (in shares)		62
Vesting of restricted stock units	0	$ 1	(1)
Tax withholding related to net share settlements of equity awards	(649)		(649)
Ending balance (in shares) at Oct. 31, 2020		42,690
Ending balance at Oct. 31, 2020	$ 717,897	$ 427	534,646	224,663	(41,839)
Beginning balance (in shares) at Apr. 30, 2021	43,073	43,073
Beginning balance at Apr. 30, 2021	$ 822,462	$ 431	542,737	274,535	4,759
Increase (Decrease) in Stockholders' Equity
Net income	61,202			61,202
Repurchase and retirement of common stock (in shares)		(85)
Repurchase and retirement of common stock	(3,855)	$ (1)	(3,854)
Foreign currency translation adjustments	(8,233)				(8,233)
Other comprehensive income, net of tax	1,962				1,962
Equity-based compensation	1,958		1,958
Exercise of stock options (in shares)		44
Exercise of stock options	863	$ 1	862
Vesting of restricted stock units (in shares)		8
Tax withholding related to net share settlements of equity awards	(256)		(256)
Issuance of common stock pursuant to employee stock purchase plan (in shares)		43
Issuance of common stock pursuant to employee stock purchase plan	1,140		1,140
Ending balance (in shares) at Jul. 31, 2021		43,083
Ending balance at Jul. 31, 2021	$ 877,243	$ 431	542,587	335,737	(1,512)
Beginning balance (in shares) at Apr. 30, 2021	43,073	43,073
Beginning balance at Apr. 30, 2021	$ 822,462	$ 431	542,737	274,535	4,759
Increase (Decrease) in Stockholders' Equity
Net income	135,563
Foreign currency translation adjustments	(4,119)
Other comprehensive income, net of tax	$ 5,251
Ending balance (in shares) at Oct. 31, 2021	43,052	43,052
Ending balance at Oct. 31, 2021	$ 951,351	$ 431	534,931	410,098	5,891
Beginning balance (in shares) at Jul. 31, 2021		43,083
Beginning balance at Jul. 31, 2021	877,243	$ 431	542,587	335,737	(1,512)
Increase (Decrease) in Stockholders' Equity
Net income	74,361			74,361
Repurchase and retirement of common stock (in shares)		(195)
Repurchase and retirement of common stock	(9,269)	$ (2)	(9,267)
Foreign currency translation adjustments	4,114				4,114
Other comprehensive income, net of tax	3,289				3,289
Equity-based compensation	3,215		3,215
Exercise of stock options (in shares)		52
Exercise of stock options	977	$ 1	976
Vesting of restricted stock units (in shares)		112
Vesting of restricted stock units	0	$ 1	(1)
Tax withholding related to net share settlements of equity awards	$ (2,579)		(2,579)
Ending balance (in shares) at Oct. 31, 2021	43,052	43,052
Ending balance at Oct. 31, 2021	$ 951,351	$ 431	$ 534,931	$ 410,098	$ 5,891