CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 938,735	$ 873,800	$ 1,757,779	$ 1,626,307
Cost of sales	431,103	403,707	847,104	789,362
Gross profit	507,632	470,093	910,675	836,945
Selling, general and administrative expenses	251,866	225,375	589,195	541,229
Income from operations	255,766	244,718	321,480	295,716
Interest income	(848)	(906)	(5,244)	(3,306)
Interest expense	128	970	2,798	3,844
Other income, net	(117)	(13)	(295)	(213)
Total other (income) expense, net	(837)	51	(2,741)	325
Income before income taxes	256,603	244,667	324,221	295,391
Income tax expense	55,010	48,293	64,169	55,052
Net income	201,593	196,374	260,052	240,339
Other comprehensive income (loss), net of tax
Unrealized (loss) gain on cash flow hedges	(973)		207
Unrealized (loss) gain on cash flow hedges		(3,128)		998
Foreign currency translation gain (loss)	2,667	781	(656)	(10,543)
Total other comprehensive income (loss)	1,694	(2,347)	(449)	(9,545)
Comprehensive income	$ 203,287	$ 194,027	$ 259,603	$ 230,794
Net income per share
Basic (in dollars per share)	$ 7.21	$ 6.74	$ 9.12	$ 8.06
Diluted (in dollars per share)	$ 7.14	$ 6.68	$ 9.02	$ 7.99
Weighted-average common shares outstanding
Basic (in shares)	27,978	29,157	28,515	29,807
Diluted (in shares)	28,249	29,397	28,832	30,063