Investments (Aggregate Carrying And Approximate Market Values Of Available-For-Sale Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 1,389,318	$ 1,128,163
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	26,368	49,336
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	7,521	702
Debt Securities, Available-for-sale	1,408,165	1,176,797
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	263,809	266,483
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	8,622	11,467
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	215	139
Debt Securities, Available-for-sale	272,216	277,811
U.S. Government agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	1,085,092	815,682
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	16,146	34,807
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	6,927	105
Debt Securities, Available-for-sale	1,094,311	850,384
Private label
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	8,555	9,976
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	553	916
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	0	0
Debt Securities, Available-for-sale	9,108	10,892
Trust preferred securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	4,570	4,557
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	0	0
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	367	457
Debt Securities, Available-for-sale	4,203	4,100
Corporate securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	27,292	31,465
Available-for-sale debt securities, accumulated gross unrealized gain, before tax	1,047	2,146
Available-for-sale debt securities, accumulated gross unrealized loss, before tax	12	1
Debt Securities, Available-for-sale	$ 28,327	$ 33,610

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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