CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net Income (Loss)	$ 40,443	$ 102,461	$ 111,726	$ 172,030
Amortization of unrecognized net periodic benefit credit, net of tax of: (2023 - Three-month period $85, Six-month period $171; 2022 - Three-month period $49, Six-month period $97)
Net actuarial gain	(247)	(140)	(494)	(281)
Interest rate swap and foreign currency translation:
Change in unrealized income (loss) on interest rate swap, net of tax of: (2023 - Three-month period $11, Six-month period $150; 2022 - Three-month period $121, Six-month period $638)	31	344	(421)	1,802
Change in foreign currency translation, net of tax of: (2023 - Three-month period $141, Six-month period $135; 2022 - Three-month period $194, Six-month period $86)	399	(553)	381	(246)
OTHER COMPREHENSIVE INCOME (LOSS), net of tax	183	(349)	(534)	1,275
TOTAL COMPREHENSIVE INCOME	$ 40,626	$ 102,112	$ 111,192	$ 173,305