CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
NET INCOME	$ 88,842	$ 63,691	$ 260,872	$ 148,033
Amortization of unrecognized net periodic benefit costs, net of tax of: (2022 - Three-month period $49, Nine-month period $146; 2021 - Three-month period $35, Nine-month period $104)
Net actuarial gain	(141)	(100)	(422)	(300)
Interest rate swap and foreign currency translation:
Change in unrealized income on interest rate swap, net of tax of: (2022 - Three-month period $206, Nine-month period $844; 2021 - Three-month period $46, Nine-month period $309)	581	128	2,383	869
Change in foreign currency translation, net of tax of: (2022 - Three-month period $509, Nine-month period $595; 2021 - Three-month period $288, Nine-month period $45)	(1,436)	(813)	(1,682)	128
OTHER COMPREHENSIVE INCOME (LOSS), net of tax	(996)	(785)	279	697
TOTAL COMPREHENSIVE INCOME	$ 87,846	$ 62,906	$ 261,151	$ 148,730