CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 43,905	$ 55,324	$ 39,009
Other comprehensive income (loss):
Adjustment for pension and postretirement benefit liability, net of tax of ($558) in 2018, ($140) in 2017 and $147 in 2016	1,568	233	(231)
Adjustment for interest rate swap, net of tax of ($64) in 2018, $88 in 2017 and $225 in 2016	84	(133)	(258)
Total other comprehensive income (loss), net of tax	1,652	100	(489)
Comprehensive Income	$ 45,557	$ 55,424	$ 38,520