Loans and Leases - Concessions Granted on Accruing and Nonaccrual Loans Restructured (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) loan	Mar. 31, 2019 USD ($) loan
Accrual Troubled Debt Restructuring Loans [Member]
Concessions Granted On Accruing And Nonaccrual Loans Restructured [Abstract]
No. of loans	0	0
Accrual Troubled Debt Restructuring Loans [Member] | Amortization Period Extension [Member]
Concessions Granted On Accruing And Nonaccrual Loans Restructured [Abstract]
No. of loans	0	0
Financing receivable modifications, recorded investments | $	$ 0	$ 0
Nonaccrual Troubled Debt Restructuring Loans [Member]
Concessions Granted On Accruing And Nonaccrual Loans Restructured [Abstract]
No. of loans	0	3
Nonaccrual Troubled Debt Restructuring Loans [Member] | Amortization Period Extension [Member]
Concessions Granted On Accruing And Nonaccrual Loans Restructured [Abstract]
No. of loans	0	3
Financing receivable modifications, recorded investments | $	$ 0	$ 2,269
Commercial Financial And Agricultural [Member] | Nonaccrual Troubled Debt Restructuring Loans [Member]
Concessions Granted On Accruing And Nonaccrual Loans Restructured [Abstract]
No. of loans	0	2
Commercial Financial And Agricultural [Member] | Nonaccrual Troubled Debt Restructuring Loans [Member] | Amortization Period Extension [Member]
Concessions Granted On Accruing And Nonaccrual Loans Restructured [Abstract]
No. of loans		2
Financing receivable modifications, recorded investments | $		$ 956
Real-Estate Commercial [Member] | Nonaccrual Troubled Debt Restructuring Loans [Member]
Concessions Granted On Accruing And Nonaccrual Loans Restructured [Abstract]
No. of loans	0	1
Real-Estate Commercial [Member] | Nonaccrual Troubled Debt Restructuring Loans [Member] | Amortization Period Extension [Member]
Concessions Granted On Accruing And Nonaccrual Loans Restructured [Abstract]
No. of loans		1
Financing receivable modifications, recorded investments | $		$ 1,313