CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
CONSOLIDATED STATEMENTS OF INCOME
NET SALES	$ 717,476	$ 651,286	$ 818,166
COSTS OF OPERATIONS	647,624	572,928	721,678
GROSS PROFIT	69,852	78,358	96,488
OPERATING EXPENSES:
Selling, general and administrative expenses	46,233	39,714	43,394
NON-OPERATING (INCOME) EXPENSES:
Interest expense, net	1,355	1,215	2,378
Other (income) expense, net	498	(668)	331
Total expense, net	48,086	40,261	46,103
INCOME BEFORE INCOME TAXES	21,766	38,097	50,385
INCOME TAX PROVISION	5,511	8,267	11,274
NET INCOME	$ 16,255	$ 29,830	$ 39,111
INCOME PER COMMON SHARE (in dollars per share)	$ 1.42	$ 2.62	$ 3.43
DILUTED INCOME PER COMMON SHARE (in dollars per share)	1.42	2.62	3.43
CASH DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.72	$ 0.72	$ 0.72
WEIGHTED AVERAGE SHARES OUTSTANDING:
Basic (in shares)	11,411	11,405	11,400
Diluted (in shares)	11,411	11,405	11,400