Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 6,505	$ 6,050	$ 15,466	$ 12,216
Reclassification of pension and postretirement adjustments into earnings, net of $42 and $85 tax benefit in the three and six months ended June 30, 2021, respectively, and net of $28 and $73 tax benefit in the three and six months ended June 30, 2020, respectively.	143	101	286	256
Total other comprehensive income	143	101	286	256
Comprehensive income	$ 6,648	$ 6,151	$ 15,752	$ 12,472