Loans (Recorded Investment By Loan Grade) (Details) - USD ($)		Sep. 30, 2019		Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Recorded Investment		$ 6,423,755,000		$ 5,709,798,000
Recorded Investment		6,403,647,000		5,692,132,000
Construction Real Estate Commercial [Domain]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Recorded Investment		224,380,000		176,101,000
Recorded Investment		223,603,000		175,300,000
Residential Real Estate Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Recorded Investment		466,855,000		430,880,000
Recorded Investment		465,656,000		429,730,000
Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Recorded Investment	[1]	1,605,464,000		1,287,795,000
Recorded Investment	[1]	1,599,697,000		1,283,045,000
Finance Leases Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Recorded Investment		31,162,000		2,299,000
Recorded Investment		31,132,000		2,273,000
5 Rated [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		43,341,000		16,048,000
5 Rated [Member] | Construction Real Estate Commercial [Domain]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		3,852,000		1,560,000
5 Rated [Member] | Residential Real Estate Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		1,001,000		272,000
5 Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		27,059,000	[2]	11,509,000	[3]
5 Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		11,429,000	[2]	2,707,000	[3]
5 Rated [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		0		0
6 Rated [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		1,594,000		485,000
6 Rated [Member] | Construction Real Estate Commercial [Domain]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment				0
6 Rated [Member] | Residential Real Estate Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		33,000		41,000
6 Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		315,000	[2]	444,000	[3]
6 Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment	[2]	1,246,000
6 Rated [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		0		0
Impaired [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		74,522,000		48,218,000
Impaired [Member] | Construction Real Estate Commercial [Domain]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		1,868,000		1,866,000
Impaired [Member] | Residential Real Estate Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		2,238,000		2,732,000
Impaired [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		31,529,000	[2]	15,194,000	[3]
Impaired [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		38,799,000	[2]	28,426,000	[3]
Impaired [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		88,000		0
Purchased credit impaired [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		19,180,000		3,961,000
Purchased credit impaired [Member] | Construction Real Estate Commercial [Domain]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		1,288,000		503,000
Purchased credit impaired [Member] | Residential Real Estate Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		1,926,000		251,000
Purchased credit impaired [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment	[2]	4,803,000		148,000
Purchased credit impaired [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment	[2]	10,595,000		3,059,000
Purchased credit impaired [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment				0
Pass Rated [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		3,334,766,000		2,905,752,000
Pass Rated [Member] | Construction Real Estate Commercial [Domain]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		217,372,000		172,172,000
Pass Rated [Member] | Residential Real Estate Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		461,657,000		427,584,000
Pass Rated [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment	[2]	1,081,836,000		1,050,094,000
Pass Rated [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment	[2]	1,543,395,000		1,253,603,000
Pass Rated [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total ending loan balance, recorded investment		30,506,000		2,299,000
Recorded Investment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Recorded Investment		3,473,403,000		2,974,464,000
Recorded Investment [Member] | Construction Real Estate Commercial [Domain]
Financing Receivable, Credit Quality Indicator [Line Items]
Recorded Investment		224,380,000		176,101,000
Recorded Investment [Member] | Residential Real Estate Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Recorded Investment		466,855,000		430,880,000
Recorded Investment [Member] | Commercial, Financial, and Agricultural [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Recorded Investment	[2]	1,145,542,000		1,077,389,000
Recorded Investment [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Recorded Investment	[2]	1,605,464,000		1,287,795,000
Recorded Investment [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Recorded Investment		31,162,000		2,299,000
Financial Asset Acquired with Credit Deterioration [Member] | Nonperforming Financial Instruments [Member] | Purchased credit impaired [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Recorded Investment		11,000		475,000
Total ending loan balance, recorded investment		$ 11,000		$ 475,000

[1] 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.

[2]  * 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.

[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.