Loans and Asset Quality Information - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) loan	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Loans and Leases Receivable Disclosure [Line Items]
PPP loans	$ 240,500
Loans pledged as collateral	4,000,000	$ 4,000,000
Payments that exceeded carrying amount of PCI loans	500	406	$ 772
Loan discount accretion income	397	348	493
Additional loan interest income	89	58	279
Recovery	14
Interest income on restructured loans	$ 1,100	1,300	1,500
Deferral period for payment deferrals	90 days
Number of loans with payment deferrals | loan	38
Remaining payment deferrals	$ 16,600
SBA Loans
Loans and Leases Receivable Disclosure [Line Items]
Remaining unaccreted discount	7,300	7,100
Purchased Non-Impaired Loans
Loans and Leases Receivable Disclosure [Line Items]
Remaining unaccreted discount	7,900	11,100	$ 15,000
SBA PPP loans
Loans and Leases Receivable Disclosure [Line Items]
Unamortized net deferred loan fees	6,000
Credit Card Loans
Loans and Leases Receivable Disclosure [Line Items]
Loans	33,200	30,900
Real estate – mortgage – residential (1-4 family) first mortgages
Loans and Leases Receivable Disclosure [Line Items]
Presold mortgages in process of settlement	1,900	600
Officers And Directors
Loans and Leases Receivable Disclosure [Line Items]
Due from related parties	3,600	$ 5,300
Loans and advances during the period	2,200
Repayments received from related parties	$ 3,900