Loans (Aging Of Recorded Investment In Past Due Loans) (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2019		Jun. 30, 2018	Jun. 30, 2019		Jun. 30, 2018	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		$ 19,254			$ 19,254			$ 29,919
Past due nonaccrual loans and loans past due 90 days or more and accruing		27,582	[1]		27,582	[1]		19,602	[2]
Total loans past due		46,836			46,836			49,521
Total current		6,350,847			6,350,847			5,660,277
Recorded Investment		6,397,683			6,397,683			5,709,798
Loans past due 90 days or more and accruing		2,471			2,471			2,302
Impaired Financing Receivable, Recorded Investment, Nonaccrual loans which are current in regards to contractual P&I payments		41,600			41,600			50,700
Financing Receivable, Modifications, Recorded Investment, During Period		5,244		$ 2,374	9,182		$ 3,767
Construction Real Estate Commercial [Domain]
Financing Receivable, Past Due [Line Items]
Past due nonaccrual loans and loans past due 90 days or more and accruing		1,748	[1]		1,748	[1]		1,635	[2]
Total loans past due		1,748			1,748			1,635
Total current		221,626			221,626			174,466
Recorded Investment		223,374			223,374			176,101
Loans past due 90 days or more and accruing		224			224			0
Financing Receivable, Modifications, Recorded Investment, During Period					456		0
Commercial Financial And Agricultural [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		402			402			4,786
Past due nonaccrual loans and loans past due 90 days or more and accruing		10,672	[1]		10,672	[1]		1,375	[2]
Total loans past due		11,074			11,074			6,161
Total current		1,153,378			1,153,378			1,071,228
Loans past due 90 days or more and accruing		25			25			10
Financing Receivable, Modifications, Recorded Investment, During Period		2,444		149	2,900		193
Construction Real Estate - Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		114			114			133
Past due nonaccrual loans and loans past due 90 days or more and accruing		301	[1]		301	[1]		20	[2]
Total loans past due		415			415			153
Total current		89,292			89,292			70,539
Recorded Investment		89,707			89,707			70,692
Loans past due 90 days or more and accruing		0			0			20
Financing Receivable, Modifications, Recorded Investment, During Period		71			71		0
Construction Real Estate - Installment [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		29			29			28
Past due nonaccrual loans and loans past due 90 days or more and accruing	[2]							19
Total loans past due		29			29			47
Total current		1,963			1,963			2,393
Recorded Investment		1,992			1,992			2,440
Loans past due 90 days or more and accruing		0			0			0
Financing Receivable, Modifications, Recorded Investment, During Period				14	0		14
Residential Real Estate Commercial [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		39			39			683
Past due nonaccrual loans and loans past due 90 days or more and accruing		811	[1]		811	[1]		1,104	[2]
Total loans past due		850			850			1,787
Total current		477,495			477,495			429,093
Recorded Investment		478,345			478,345			430,880
Loans past due 90 days or more and accruing		0			0
Financing Receivable, Modifications, Recorded Investment, During Period		36			36		0
Residential Real Estate - Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		9,322			9,322			13,210
Past due nonaccrual loans and loans past due 90 days or more and accruing		9,574	[1]		9,574	[1]		8,553	[2]
Total loans past due		18,896			18,896			21,763
Total current		1,150,805			1,150,805			1,113,742
Recorded Investment		1,169,701			1,169,701			1,135,505
Loans past due 90 days or more and accruing		1,061			1,061			1,124
Financing Receivable, Modifications, Recorded Investment, During Period		374		317	673		961
Residential Real Estate - HELOC [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		235			235			620
Past due nonaccrual loans and loans past due 90 days or more and accruing		843	[1]		843	[1]		907	[2]
Total loans past due		1,078			1,078			1,527
Total current		239,263			239,263			214,915
Recorded Investment		240,341			240,341			216,442
Loans past due 90 days or more and accruing		55			55			9
Financing Receivable, Modifications, Recorded Investment, During Period		166		452	236		791
Residential Real Estate - Installment [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		82			82			155
Past due nonaccrual loans and loans past due 90 days or more and accruing		337	[1]		337	[1]		274	[2]
Total loans past due		419			419			429
Total current		13,004			13,004			13,934
Recorded Investment		13,423			13,423			14,363
Loans past due 90 days or more and accruing		0			0			24
Financing Receivable, Modifications, Recorded Investment, During Period		410		75	596		121
Commercial Financial And Agricultural [Member]
Financing Receivable, Past Due [Line Items]
Recorded Investment	[3]	1,164,452			1,164,452			1,077,389
Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		3,026			3,026			780
Past due nonaccrual loans and loans past due 90 days or more and accruing		1,565	[1]		1,565	[1]		3,584	[2]
Total loans past due		4,591			4,591			4,364
Total current		1,613,361			1,613,361			1,283,431
Recorded Investment	[3]	1,617,952			1,617,952			1,287,795
Loans past due 90 days or more and accruing		606			606
Financing Receivable, Modifications, Recorded Investment, During Period		780		589	2,995		720
Consumer [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		6,005			6,005			9,524
Past due nonaccrual loans and loans past due 90 days or more and accruing		1,731	[1]		1,731	[1]		2,131	[2]
Total loans past due		7,736			7,736			11,655
Total current		1,359,588			1,359,588			1,284,237
Recorded Investment		1,367,324			1,367,324			1,295,892
Loans past due 90 days or more and accruing		500			500			1,115
Financing Receivable, Modifications, Recorded Investment, During Period		963		778	1,219		967
Finance Leases Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		0			0			0
Past due nonaccrual loans and loans past due 90 days or more and accruing		0	[1]		0	[1]		0	[2]
Total loans past due		0			0			0
Total current		31,072			31,072			2,299
Recorded Investment		31,072			31,072			2,299
Loans past due 90 days or more and accruing		0			0			$ 0
Accruing Financing Receivable Modifications [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		2,397		1,223	3,092		1,511
Accruing Financing Receivable Modifications [Member] | Construction Real Estate Commercial [Domain]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period					456		0
Accruing Financing Receivable Modifications [Member] | Commercial Financial And Agricultural [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		1,802		123	1,801		123
Accruing Financing Receivable Modifications [Member] | Construction Real Estate - Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		71		0	71		0
Accruing Financing Receivable Modifications [Member] | Construction Real Estate - Installment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		0		14	0		14
Accruing Financing Receivable Modifications [Member] | Residential Real Estate Commercial [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period					0		0
Accruing Financing Receivable Modifications [Member] | Residential Real Estate - Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		0		93	54		93
Accruing Financing Receivable Modifications [Member] | Residential Real Estate - HELOC [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		99		409	100		661
Accruing Financing Receivable Modifications [Member] | Residential Real Estate - Installment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		365		71	550		104
Accruing Financing Receivable Modifications [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period				455	0		455
Accruing Financing Receivable Modifications [Member] | Consumer [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		60		58	60		61
Nonaccruing Financing Receivable Modifications [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		2,847		1,151	6,090		2,256
Nonaccruing Financing Receivable Modifications [Member] | Construction Real Estate Commercial [Domain]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period					0		0
Nonaccruing Financing Receivable Modifications [Member] | Commercial Financial And Agricultural [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		642		26	1,099		70
Nonaccruing Financing Receivable Modifications [Member] | Construction Real Estate - Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period					0		0
Nonaccruing Financing Receivable Modifications [Member] | Construction Real Estate - Installment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period					0		0
Nonaccruing Financing Receivable Modifications [Member] | Residential Real Estate Commercial [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		36			36		0
Nonaccruing Financing Receivable Modifications [Member] | Residential Real Estate - Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		374		224	619		868
Nonaccruing Financing Receivable Modifications [Member] | Residential Real Estate - HELOC [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		67		43	136		130
Nonaccruing Financing Receivable Modifications [Member] | Residential Real Estate - Installment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		45		4	46		17
Nonaccruing Financing Receivable Modifications [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		780		134	2,995		265
Nonaccruing Financing Receivable Modifications [Member] | Consumer [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period		$ 903		$ 720	$ 1,159		$ 906

[1] 1) Includes an aggregate of $2.5 million of loans past due 90 days or more and accruing. The remaining loans were past due nonaccrual loans.(2) Includes an aggregate of $41.6 million of nonaccrual loans which were current in regards to contractual principal and interest payments

[2] 1) Includes an aggregate of $2.3 million of loans past due 90 days or more and accruing. The remaining loans were past due nonaccrual loans.(2) Includes an aggregate of $50.7 million of nonaccrual loans which were current in regards to contractual principal and interest payments.

[3] Included within each of commercial, financial and agricultural loans and commercial real estate loans is an immaterial amount of consumer loans that are not broken out by class.