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
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
NET INCOME	$ 15,880	$ 24,376	$ 17,782	$ 29,264
Pension and other postretirement benefit plans:
Net actuarial gain (loss), net of tax of: (2020 - Three-month period $-, Six-month period $3; 2019 - Three-month period $20, Six-month period $210)		(58)	(8)	603
Pension settlement expense, net of tax of: (2020 - Three-month period $-, Six-month period $23; 2019 - Three-month period $72, Six-month period $421)		206	66	1,213
Amortization of unrecognized net periodic benefit cost (credit), net of tax of: (2020 - Three-month period $39, Six-month period $76; 2019 - Three-month period $77, Six-month period $177)
Net actuarial (gain) loss	(109)	229	(217)	524
Prior service credit		(6)		(12)
Interest rate swap and foreign currency translation:
Change in unrealized loss on interest rate swap, net of tax of: (2020 - Three-month period $766, Six-month period $414; 2019 - Three-month period $187, Six-month period $305)	(174)	(528)	(1,171)	(860)
Change in foreign currency translation, net of tax of: (2020 - Three-month period $842, Six-month period $340; 2019 - Three-month period $41, Six-month period $120)	457	116	(963)	341
OTHER COMPREHENSIVE INCOME (LOSS), net of tax	174	(41)	(2,293)	1,809
TOTAL COMPREHENSIVE INCOME	$ 16,054	$ 24,335	$ 15,489	$ 31,073