Loans and Leases - Collateral Dependent Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	$ 34,528	$ 31,692
Total nonaccrual loans (excluding leases)	34,498	31,485
Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	33,846	30,009
Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	477	1,194
None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	175	282
Commercial Financial And Agricultural [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	933	2,827
Commercial Financial And Agricultural [Member] | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	281	1,351
Commercial Financial And Agricultural [Member] | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	477	1,194
Commercial Financial And Agricultural [Member] | None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	175	282
Real-Estate Commercial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	28,296	22,739
Real-Estate Commercial [Member] | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	28,296	22,739
Real-Estate Commercial [Member] | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0	0
Real-Estate Commercial [Member] | None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0	0
Real Estate Residential Secured For Business Purpose [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	2,469	2,786
Real Estate Residential Secured For Business Purpose [Member] | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	2,469	2,786
Real Estate Residential Secured For Business Purpose [Member] | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0	0
Real Estate Residential Secured For Business Purpose [Member] | None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0	0
Real Estate Residential Secured For Personal Purpose [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	2,079	2,086
Real Estate Residential Secured For Personal Purpose [Member] | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	2,079	2,086
Real Estate Residential Secured For Personal Purpose [Member] | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0	0
Real Estate Residential Secured For Personal Purpose [Member] | None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0	0
Real Estate Home Equity Secured For Personal Purpose [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	721	1,047
Real Estate Home Equity Secured For Personal Purpose [Member] | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	721	1,047
Real Estate Home Equity Secured For Personal Purpose [Member] | Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	0	0
Real Estate Home Equity Secured For Personal Purpose [Member] | None
Financing Receivable, Allowance for Credit Loss [Line Items]
Total nonaccrual loans	$ 0	$ 0