v3.26.1
Investments (Aggregate Carrying And Approximate Market Values Of Available-For-Sale Securities) (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]    
Total $ 1,546,565 $ 1,602,721
Gross Unrealized Gains 3,972 8,546
Gross Unrealized Losses 109,439 107,909
Estimated Fair Value 1,441,098 1,503,358
Obligations of states and political subdivisions    
Debt Securities, Available-for-sale [Line Items]    
Total 188,054 189,276
Gross Unrealized Gains 171 538
Gross Unrealized Losses 10,926 10,090
Estimated Fair Value 177,299 179,724
U.S. government agencies    
Debt Securities, Available-for-sale [Line Items]    
Total 1,332,163 1,387,057
Gross Unrealized Gains 3,620 7,836
Gross Unrealized Losses 97,686 97,104
Estimated Fair Value 1,238,097 1,297,789
Private label    
Debt Securities, Available-for-sale [Line Items]    
Total 5,065 5,068
Gross Unrealized Gains 0 0
Gross Unrealized Losses 55 36
Estimated Fair Value 5,010 5,032
Trust preferred securities    
Debt Securities, Available-for-sale [Line Items]    
Total 4,614 4,612
Gross Unrealized Gains 0 0
Gross Unrealized Losses 217 188
Estimated Fair Value 4,397 4,424
Corporate securities    
Debt Securities, Available-for-sale [Line Items]    
Total 16,669 16,708
Gross Unrealized Gains 181 172
Gross Unrealized Losses 555 491
Estimated Fair Value $ 16,295 $ 16,389