Consolidated Income Statements - Unaudited - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
REVENUES	$ 136,431,000	$ 128,219,000	$ 274,043,000	$ 256,678,000
Cost of revenues	110,679,000	102,307,000	219,508,000	205,184,000
Gross profit	25,752,000	25,912,000	54,535,000	51,494,000
General and administrative expenses	13,670,000	14,644,000	28,299,000	28,105,000
Income before income tax provision	12,082,000	11,268,000	26,236,000	23,389,000
Income tax provision	3,689,000	4,316,000	9,068,000	8,946,000
NET INCOME	$ 8,393,000	$ 6,952,000	$ 17,168,000	$ 14,443,000
Net income per common and common equivalent share
Basic	$ 0.45	$ 0.36	$ 0.91	$ 0.74
Diluted	$ 0.44	$ 0.35	$ 0.90	$ 0.73
Weighted average common and common equivalent shares
Basic	18,759,000	19,581,000	18,785,000	19,577,000
Diluted	18,966,000	19,733,000	18,983,000	19,743,000