Loans and Leases - Collateral Dependent Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	$ 36,626	$ 38,578
Total nonaccrual loans (excluding leases)	36,131
Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	34,199
Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	1,351
None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	581
Commercial Financial And Agricultural [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	3,934	3,442
Commercial Financial And Agricultural [Member] | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	2,002
Commercial Financial And Agricultural [Member] | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	1,351
Commercial Financial And Agricultural [Member] | None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	581
Real-Estate Commercial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	28,827	27,928
Real-Estate Commercial [Member] | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	28,827
Real-Estate Commercial [Member] | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0
Real-Estate Commercial [Member] | None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0
Real Estate Residential Secured For Business Purpose [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	1,270	2,980
Real Estate Residential Secured For Business Purpose [Member] | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	1,270
Real Estate Residential Secured For Business Purpose [Member] | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0
Real Estate Residential Secured For Business Purpose [Member] | None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0
Real Estate Residential Secured For Personal Purpose [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	1,280	2,038
Real Estate Residential Secured For Personal Purpose [Member] | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	1,280
Real Estate Residential Secured For Personal Purpose [Member] | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0
Real Estate Residential Secured For Personal Purpose [Member] | None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0
Real Estate Home Equity Secured For Personal Purpose [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	820	$ 1,427
Real Estate Home Equity Secured For Personal Purpose [Member] | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	820
Real Estate Home Equity Secured For Personal Purpose [Member] | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0
Real Estate Home Equity Secured For Personal Purpose [Member] | None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	$ 0