CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
CONDENSED CONSOLIDATED STATEMENTS OF INCOME
NET SALES	$ 168,366	$ 195,467	$ 472,949	$ 615,026
COSTS OF OPERATIONS	150,523	173,721	418,841	545,470
GROSS PROFIT	17,843	21,746	54,108	69,556
OPERATING EXPENSES:
Selling, general and administrative expenses	9,231	10,453	30,272	31,636
NON-OPERATING (INCOME) EXPENSES:
Interest expense, net	230	424	1,018	1,813
Other (income) expense, net	(209)	231	(393)	542
Total expense, net	9,252	11,108	30,897	33,991
INCOME BEFORE INCOME TAXES	8,591	10,638	23,211	35,565
INCOME TAX PROVISION	2,038	2,562	5,401	8,146
NET INCOME	$ 6,553	$ 8,076	$ 17,810	$ 27,419
BASIC INCOME PER COMMON SHARE (in dollars per share)	$ 0.57	$ 0.71	$ 1.56	$ 2.41
CASH DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.18	$ 0.18	$ 0.54	$ 0.54
WEIGHTED AVERAGE SHARES OUTSTANDING:
Basic (in shares)	11,405	11,400	11,405	11,400