CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
CONDENSED CONSOLIDATED STATEMENTS OF INCOME
NET SALES	$ 128,529	$ 222,346	$ 304,583	$ 419,559
COSTS OF OPERATIONS	110,802	197,133	268,318	371,749
GROSS PROFIT	17,727	25,213	36,265	47,810
OPERATING EXPENSES:
Selling, general and administrative expenses	10,067	10,968	21,041	21,183
NON-OPERATING (INCOME) EXPENSES:
Interest expense, net	429	721	788	1,389
Other (income) expense, net	(275)	57	(184)	311
Total expense, net	10,221	11,746	21,645	22,883
INCOME BEFORE INCOME TAXES	7,506	13,467	14,620	24,927
INCOME TAX PROVISION	1,680	2,784	3,363	5,584
NET INCOME	$ 5,826	$ 10,683	$ 11,257	$ 19,343
BASIC INCOME PER COMMON SHARE (in dollars per share)	$ 0.51	$ 0.94	$ 0.99	$ 1.70
CASH DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.18	$ 0.18	$ 0.36	$ 0.36
WEIGHTED AVERAGE SHARES OUTSTANDING:
Basic (in shares)	11,405	11,400	11,405	11,400