UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Net sales	$ 345,043	$ 371,363	$ 701,575	$ 744,719
Cost of sales	259,543	283,792	535,372	579,555
Gross profit	85,500	87,571	166,203	165,164
Selling, general, and administrative expenses	57,705	56,340	114,671	111,004
Depreciation and amortization	2,741	2,129	5,531	4,192
Interest and financing costs	484	274	960	633
Operating expenses	60,930	58,743	121,162	115,829
Operating income	24,570	28,828	45,041	49,335
Other income (expense)	322	(141)	419	130
Earnings before tax	24,892	28,687	45,460	49,465
Provision for income taxes	6,889	11,466	12,184	18,821
Net earnings	$ 18,003	$ 17,221	$ 33,276	$ 30,644
Net earnings per common share-basic (in dollars per share)	$ 1.33	$ 1.24	$ 2.47	$ 2.21
Net earnings per common share-diluted (in dollars per share)	$ 1.33	$ 1.23	$ 2.45	$ 2.19
Weighted average common shares outstanding-basic (in shares)	13,494	13,879	13,464	13,843
Weighted average common shares outstanding-diluted (in shares)	13,586	14,008	13,597	14,021