CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Net sales	$ 1,204,199	$ 1,143,282	$ 1,057,536
Cost of sales	942,142	898,735	840,623
Gross profit	262,057	244,547	216,913
Professional and other fees	6,546	6,508	9,041
Salaries and benefits	149,304	138,086	123,151
General and administrative expenses	23,130	22,531	19,883
Depreciation and amortization	5,548	4,333	2,792
Interest and financing costs	1,778	2,379	1,948
Operating expenses	186,306	173,837	156,815
Operating income	75,751	70,710	60,098
Other income	0	7,603	0
Earnings before tax	75,751	78,313	60,098
Provision for income taxes	31,004	32,473	24,825
Net earnings	$ 44,747	$ 45,840	$ 35,273
Net earnings per common share - basic (in dollars per share)	$ 6.17	$ 6.26	$ 4.41
Net earnings per common share - diluted (in dollars per share)	$ 6.09	$ 6.19	$ 4.37
Weighted average common shares outstanding - basic (in shares)	7,256	7,318	7,927
Weighted average common shares outstanding - diluted (in shares)	7,344	7,393	7,999