Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Statement of Comprehensive Income [Abstract]
Net income	$ 390,853	$ 305,810
Reclassification adjustment for net losses on AFS securities included in net income, net of tax	5,270	39,032
Unrealized gain on AFS securities, net of tax	104,211	70,574
Change in pension surplus, net of tax	13,572	18,061
Other comprehensive income	123,053	127,667
Total comprehensive income	$ 513,906	$ 433,477