CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
NET SALES	$ 148,933	$ 148,815
COSTS OF OPERATIONS	133,538	135,845
GROSS PROFIT	15,395	12,970
OPERATING EXPENSES:
Selling, general and administrative expenses	9,044	8,010
Interest expense, net	378	198
Other (income) expense, net	(14)	(341)
Total operating expenses	9,408	7,867
INCOME BEFORE INCOME TAXES	5,987	5,103
INCOME TAX PROVISION	2,148	1,743
NET INCOME	$ 3,839	$ 3,360
BASIC INCOME PER COMMON SHARE (in dollars per share)	$ 0.34	$ 0.30
DILUTED INCOME PER COMMON SHARE (in dollars per share)	0.34	0.30
CASH DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.18	$ 0.17
WEIGHTED AVERAGE SHARES OUTSTANDING:
Basic (in shares)	11,350	11,345
Diluted (in shares)	11,380	11,373