Investments (Aggregate Carrying And Approximate Market Values Of Available-For-Sale Securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 754,954	$ 734,378
Gross Unrealized Gains	7,978	3,153
Gross Unrealized Losses	7,851	14,277
Estimated Fair Value	755,081	723,254
U.S Treasuries and U.S. Government Agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,277	5,713
Gross Unrealized Gains	23	20
Gross Unrealized Losses	0	0
Estimated Fair Value	2,300	5,733
Obligations Of States And Political Subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	123,293	128,089
Gross Unrealized Gains	2,632	1,033
Gross Unrealized Losses	285	1,052
Estimated Fair Value	125,640	128,070
U.S. Government Agencies Mortgage-backed Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	590,773	561,799
Gross Unrealized Gains	4,871	1,950
Gross Unrealized Losses	6,946	12,991
Estimated Fair Value	588,698	550,758
Private Label
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11,787	11,948
Gross Unrealized Gains	328	95
Gross Unrealized Losses	0	0
Estimated Fair Value	12,115	12,043
Trust Preferred Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,776	4,774
Gross Unrealized Gains	31	25
Gross Unrealized Losses	569	0
Estimated Fair Value	4,238	4,799
Corporate Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	16,787	16,795
Gross Unrealized Gains	93	30
Gross Unrealized Losses	1	167
Estimated Fair Value	16,879	16,658
Debt Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	749,693	729,118
Gross Unrealized Gains	7,978	3,153
Gross Unrealized Losses	7,801	14,210
Estimated Fair Value	749,870	718,061
Certificates of Deposit [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,735	3,735
Estimated Fair Value	3,735	3,735
Money Market Funds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,526	1,525
Gross Unrealized Gains	0	0
Gross Unrealized Losses	50	67
Estimated Fair Value	$ 1,476	$ 1,458

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).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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- Definition

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).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

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