Consolidated Statements of Income (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Statement [Abstract]
Revenues	$ 478,816,000	$ 429,310,000	$ 412,668,000
Cost of revenues	370,335,000	337,650,000	318,826,000
Gross profit	108,481,000	91,660,000	93,842,000
General and administrative	51,974,000	47,765,000	50,405,000
Income before income taxes	56,507,000	43,895,000	43,437,000
Income tax provision	22,115,000	17,165,000	16,885,000
Net income	$ 34,392,000	$ 26,730,000	$ 26,552,000
Net income per share:
Basic	$ 1.63	$ 1.20	$ 1.16
Diluted	$ 1.61	$ 1.19	$ 1.14
Weighted average shares outstanding:
Basic	21,104,000	22,256,000	22,952,000
Diluted	21,372,000	22,458,000	23,254,000