Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 6,050	$ 7,975	$ 12,216	$ 22,993
Reclassification of pension and postretirement adjustments into earnings, net of $28 and $73 tax benefit in the three months and six months ended June 30, 2020, respectively, net of $21 and $45 tax benefit in the three and six months ended June 30, 2019, respectively.	101	71	256	172
Total other comprehensive income	101	71	256	172
Comprehensive income	$ 6,151	$ 8,046	$ 12,472	$ 23,165