CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 408,375	$ 430,158	$ 189,580
Defined benefit plans reclassification including pension costs:
Actuarial gain	3,762	7,742	14,965
Prior service credits (costs)	8	(116)	3
Pension plan settlement	82,822	0	0
Postretirement benefits reclassification including benefit costs:
Actuarial (loss) gain	(6,031)	7,991	3,089
Interest rate swap	0	0	556
Foreign currency translation adjustment	0	9	(23)
Other comprehensive income, net of tax	80,561	15,626	18,590
Comprehensive income	$ 488,936	$ 445,784	$ 208,170