Purchased Loans - Restructured Loans by Class (Details) - Purchased $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($) loan	Dec. 31, 2016 USD ($) loan	Dec. 31, 2015 USD ($) loan
Restructured loans
Number of Loans (loans) \| loan	28	23	23
Pre-Modification Outstanding Recorded Investment	$ 6,859	$ 3,272	$ 3,815
Post-Modification Outstanding Recorded Investment	$ 5,358	$ 2,365	$ 3,026
Commercial, financial, agricultural
Restructured loans
Number of Loans (loans) \| loan	0	1	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 41	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 17	$ 0
Lease financing
Restructured loans
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
Restructured loans
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
Restructured loans
Number of Loans (loans) \| loan	23	17	15
Pre-Modification Outstanding Recorded Investment	$ 3,744	$ 1,608	$ 1,268
Post-Modification Outstanding Recorded Investment	$ 3,127	$ 1,269	$ 956
Real estate – commercial mortgage
Restructured loans
Number of Loans (loans) \| loan	5	5	8
Pre-Modification Outstanding Recorded Investment	$ 3,115	$ 1,623	$ 2,547
Post-Modification Outstanding Recorded Investment	$ 2,231	$ 1,079	$ 2,070
Installment loans to individuals
Restructured loans
Number of Loans (loans) \| loan	0	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0

Troubled Debt Restructuring Financing Receivable Modifications [Abstract]

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

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