v3.25.1
Accumulated Other Comprehensive Income (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Accumulated Other Comprehensive Income (Loss) before Tax [Roll Forward]    
Beginning Balance $ 4,234,666 $ 3,743,897
Total other comprehensive income 629 101,560
Ending Balance 4,186,763 3,967,585
Unrealized Gains (Losses) on AFS Securities    
Accumulated Other Comprehensive Income (Loss) before Tax [Roll Forward]    
Beginning Balance 11,668 (59,777)
Net change in unrealized gains 3,021 101,316
Net realized (gains) on sales of AFS securities (2,704)  
Pension benefits, net 0 0
Total other comprehensive income 317 101,316
Ending Balance 11,985 41,539
Pension Benefits    
Accumulated Other Comprehensive Income (Loss) before Tax [Roll Forward]    
Beginning Balance (16,508) (13,755)
Net change in unrealized gains 0 0
Net realized (gains) on sales of AFS securities 0  
Pension benefits, net 312 244
Total other comprehensive income 312 244
Ending Balance (16,196) (13,511)
Accumulated Other Comprehensive Income (Loss)    
Accumulated Other Comprehensive Income (Loss) before Tax [Roll Forward]    
Beginning Balance (4,840) (73,532)
Net change in unrealized gains 3,021 101,316
Net realized (gains) on sales of AFS securities (2,704)  
Pension benefits, net 312 244
Total other comprehensive income 629 101,560
Ending Balance $ (4,211) $ 28,028