Investments (Gross Unrealized Losses And Fair Value Of Investments) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Less Than Twelve Months
Estimated Fair Value	$ 121,665	$ 9,637
Unrealized Loss	10,522	10,337
Estimated Fair Value	922,544	955,196
Twelve Months or Greater
Unrealized Loss	147,541	133,941
Estimated Fair Value	1,044,209	964,833
Unrealized Loss	158,063	144,278
Obligations of states and political subdivisions
Less Than Twelve Months
Estimated Fair Value	17,733	7,591
Unrealized Loss	505	66
Estimated Fair Value	179,538	180,560
Twelve Months or Greater
Unrealized Loss	17,918	16,023
Estimated Fair Value	197,271	188,151
Unrealized Loss	18,423	16,089
U.S. Government agencies
Less Than Twelve Months
Estimated Fair Value	102,346	2,046
Unrealized Loss	10,002	10,271
Estimated Fair Value	708,833	740,914
Twelve Months or Greater
Unrealized Loss	127,750	115,482
Estimated Fair Value	811,179	742,960
Unrealized Loss	137,752	125,753
Private label
Less Than Twelve Months
Estimated Fair Value	1,586	0
Unrealized Loss	15	0
Estimated Fair Value	4,861	4,835
Twelve Months or Greater
Unrealized Loss	247	293
Estimated Fair Value	6,447	4,835
Unrealized Loss	262	293
Trust preferred securities
Less Than Twelve Months
Estimated Fair Value	0	0
Unrealized Loss	0	0
Estimated Fair Value	4,593	4,278
Twelve Months or Greater
Unrealized Loss	9	321
Estimated Fair Value	4,593	4,278
Unrealized Loss	9	321
Corporate securities
Less Than Twelve Months
Estimated Fair Value	0	0
Unrealized Loss	0	0
Estimated Fair Value	24,719	24,609
Twelve Months or Greater
Unrealized Loss	1,617	1,822
Estimated Fair Value	24,719	24,609
Unrealized Loss	$ 1,617	$ 1,822