Purchased Loans - Restructured Loans by Class (Details) - Purchased $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) loan	Dec. 31, 2017 USD ($) loan	Dec. 31, 2016 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans (loans) | loan	5	28	23
Pre-Modification Outstanding Recorded Investment	$ 712	$ 6,859	$ 3,272
Post-Modification Outstanding Recorded Investment	$ 552	$ 5,358	$ 2,365
Commercial, financial, agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans (loans) | loan	1	0	1
Pre-Modification Outstanding Recorded Investment	$ 48	$ 0	$ 41
Post-Modification Outstanding Recorded Investment	$ 44	$ 0	$ 17
Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans (loans) | loan	0	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0
Real estate – construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans (loans) | loan	0	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0
Real estate – 1-4 family mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans (loans) | loan	2	23	17
Pre-Modification Outstanding Recorded Investment	$ 142	$ 3,744	$ 1,608
Post-Modification Outstanding Recorded Investment	$ 127	$ 3,127	$ 1,269
Real estate – commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans (loans) | loan	2	5	5
Pre-Modification Outstanding Recorded Investment	$ 522	$ 3,115	$ 1,623
Post-Modification Outstanding Recorded Investment	$ 381	$ 2,231	$ 1,079
Installment loans to individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans (loans) | loan	0	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0