CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 570,582	$ 633,125	$ 408,375
Defined benefit plans reclassification including pension costs:
Actuarial gain	21	3,885	3,762
Prior service (costs) credits	(82)	12	8
Postretirement benefits reclassification including benefit costs:
Actuarial (loss) gain	(7,804)	2,239	(6,031)
Net change in unrealized gain/loss on short-term investments	(25)	25	0
Pension plan settlement	0	0	82,822
Other comprehensive (loss) income, net of tax	(7,890)	6,161	80,561
Comprehensive income	$ 562,692	$ 639,286	$ 488,936