Consolidated Income Statements - Unaudited - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
REVENUES	$ 136,028,000	$ 146,970,000	$ 265,628,000	$ 297,109,000
Cost of revenues	105,525,000	114,127,000	208,616,000	231,132,000
Gross profit	30,503,000	32,843,000	57,012,000	65,977,000
General and administrative expenses	15,560,000	16,593,000	31,145,000	32,345,000
Income before income tax provision	14,943,000	16,250,000	25,867,000	33,632,000
Income tax provision	3,078,000	3,379,000	5,700,000	7,354,000
NET INCOME	$ 11,865,000	$ 12,871,000	$ 20,167,000	$ 26,278,000
Net income per common and common equivalent share
Basic	$ 0.66	$ 0.70	$ 1.12	$ 1.42
Diluted	$ 0.65	$ 0.69	$ 1.11	$ 1.40
Weighted average common and common equivalent shares
Basic	17,937,000	18,452,000	17,960,000	18,488,000
Diluted	18,174,000	18,771,000	18,144,000	18,779,000