CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Statement of Comprehensive Income [Abstract]
Net income	$ 180,294	$ 174,685	$ 330,768	$ 313,102
Other comprehensive income (loss), net of tax
Change in unrealized holding gains (losses) on available-for-sale securities	1,092	6,261	(11,443)	12,039
Pension and other postretirement plans	308	(183)	617	(744)
Total other comprehensive income (loss), net of tax	1,400	6,078	(10,826)	11,295
Comprehensive income	$ 181,694	$ 180,763	$ 319,942	$ 324,397