CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Net sales	$ 501,913	$ 482,460	$ 752,507	$ 692,177
Cost of sales	250,026	257,343	385,655	376,435
Gross profit	251,887	225,117	366,852	315,742
Selling, general and administrative expenses	161,475	157,762	315,854	304,643
Income from operations	90,412	67,355	50,998	11,099
Interest income	(814)	(509)	(2,400)	(961)
Interest expense	1,640	1,531	2,874	2,538
Other (income) expense, net	(189)	12	(200)	(212)
Total other expense, net	637	1,034	274	1,365
Income before income taxes	89,775	66,321	50,724	9,734
Income tax expense	15,403	16,762	6,759	2,296
Net income	74,372	49,559	43,965	7,438
Other comprehensive (loss) income, net of tax
Unrealized (loss) gain on cash flow hedges	(1,197)	(911)	4,126	(4,683)
Foreign currency translation (loss) gain	(3,861)	2,968	(11,324)	4,518
Total other comprehensive (loss) income	(5,058)	2,057	(7,198)	(165)
Comprehensive income	$ 69,314	$ 51,616	$ 36,767	$ 7,273
Net income per share
Basic (in dollars per share)	$ 2.49	$ 1.55	$ 1.46	$ 0.23
Diluted (in dollars per share)	$ 2.48	$ 1.54	$ 1.45	$ 0.23
Weighted-average common shares outstanding
Basic (in shares)	29,849	32,015	30,134	32,003
Diluted (in shares)	30,028	32,272	30,327	32,256