UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Net sales	$ 326,657	$ 298,644	$ 996,622	$ 904,796
Cost of sales	252,871	234,584	773,239	709,685
Gross profit	73,786	64,060	223,383	195,111
Professional and other fees	1,397	1,882	4,918	4,913
Salaries and benefits	42,385	37,372	124,479	108,326
General and administrative expenses	6,378	5,434	20,424	17,390
Depreciation and amortization	1,910	1,331	5,408	3,739
Interest and financing costs	409	396	1,158	1,371
Operating expenses	52,479	46,415	156,387	135,739
Operating income	21,307	17,645	66,996	59,372
Other income	0	0	380	0
Earnings before tax	21,307	17,645	67,376	59,372
Provision for income taxes	8,687	7,348	27,310	24,582
Net earnings	$ 12,620	$ 10,297	$ 40,066	$ 34,790
Net earnings per common share-basic (in dollars per share)	$ 1.83	$ 1.41	$ 5.77	$ 4.79
Net earnings per common share-diluted (in dollars per share)	$ 1.81	$ 1.40	$ 5.71	$ 4.74
Weighted average common shares outstanding-basic (in shares)	6,896	7,280	6,946	7,260
Weighted average common shares outstanding-diluted (in shares)	6,960	7,329	7,013	7,336