CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales	$ 873,800	$ 810,478	$ 1,626,307	$ 1,502,655
Cost of sales	403,707	387,007	789,362	763,442
Gross profit	470,093	423,471	836,945	739,213
Selling, general and administrative expenses	225,375	230,280	541,229	534,923
Income from operations	244,718	193,191	295,716	204,290
Interest income	(906)	(590)	(3,306)	(1,551)
Interest expense	970	1,506	3,844	4,044
Other income, net	(13)	(778)	(213)	(990)
Total other expense, net	51	138	325	1,503
Income before income taxes	244,667	193,053	295,391	202,787
Income tax expense	48,293	106,712	55,052	109,008
Net income	196,374	86,341	240,339	93,779
Other comprehensive (loss) income, net of tax
Unrealized (loss) gain on cash flow hedges	(3,128)	2,509	998	(2,174)
Foreign currency translation gain (loss)	781	2,037	(10,543)	6,555
Total other comprehensive (loss) income	(2,347)	4,546	(9,545)	4,381
Comprehensive income	$ 194,027	$ 90,887	$ 230,794	$ 98,160
Net income per share
Basic (in dollars per share)	$ 6.74	$ 2.71	$ 8.06	$ 2.93
Diluted (in dollars per share)	$ 6.68	$ 2.69	$ 7.99	$ 2.91
Weighted-average common shares outstanding
Basic (in shares)	29,157	31,863	29,807	31,956
Diluted (in shares)	29,397	32,041	30,063	32,186