Credit Quality of Loans and Allowance for Loan Losses - Roll Forward of Activity In Allowance for Loan Losses (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	$ 24,372	$ 19,011
Charge-offs	(19,947)	(4,180)
Recoveries	1,027	437
Provision	19,601	8,000
Ending balance	25,053	23,268
Ending balance: individually evaluated for impairment	4,252	3,837
Ending balance: collectively evaluated for impairment	20,801	19,431
Loans:
Ending balance	1,235,969	1,272,800	$ 1,284,082
Ending balance: individually evaluated for impairment	52,843	60,477
Ending balance: collectively evaluated for impairment	1,182,637	1,211,665
Ending balance: loans acquired with deteriorated credit quality	489	658
Commercial, financial and agricultural
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	16,057	11,268
Charge-offs	(15,106)	(2,957)
Recoveries	537	193
Provision	17,413	6,747
Ending balance	18,901	15,251
Ending balance: individually evaluated for impairment	3,254	1,105
Ending balance: collectively evaluated for impairment	15,647	14,146
Loans:
Ending balance	447,482	463,031	459,574
Ending balance: individually evaluated for impairment	30,892	29,887
Ending balance: collectively evaluated for impairment	416,590	433,144
Ending balance: loans acquired with deteriorated credit quality	0	0
Real estate - construction
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	585	819
Charge-offs	(70)	0
Recoveries	0	0
Provision	28	(478)
Ending balance	543	341
Ending balance: individually evaluated for impairment	17	0
Ending balance: collectively evaluated for impairment	526	341
Loans:
Ending balance	90,088	96,365	100,959
Ending balance: individually evaluated for impairment	2,416	10
Ending balance: collectively evaluated for impairment	87,672	96,355
Ending balance: loans acquired with deteriorated credit quality	0	0
Real estate – commercial
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	5,384	4,614
Charge-offs	(3,618)	(208)
Recoveries	158	115
Provision	2,024	1,042
Ending balance	3,948	5,563
Ending balance: individually evaluated for impairment	904	2,270
Ending balance: collectively evaluated for impairment	3,044	3,293
Loans:
Ending balance	473,046	464,853	481,155
Ending balance: individually evaluated for impairment	18,132	28,285
Ending balance: collectively evaluated for impairment	454,488	435,985
Ending balance: loans acquired with deteriorated credit quality	426	583
Real estate – residential
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	940	816
Charge-offs	(293)	(24)
Recoveries	97	4
Provision	(40)	(97)
Ending balance	704	699
Ending balance: individually evaluated for impairment	7	194
Ending balance: collectively evaluated for impairment	697	505
Loans:
Ending balance	155,676	155,653	157,872
Ending balance: individually evaluated for impairment	1,031	1,831
Ending balance: collectively evaluated for impairment	154,582	153,747
Ending balance: loans acquired with deteriorated credit quality	63	75
Installment loans to individuals
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	1,395	1,468
Charge-offs	(860)	(991)
Recoveries	235	125
Provision	159	781
Ending balance	929	1,383
Ending balance: individually evaluated for impairment	69	268
Ending balance: collectively evaluated for impairment	860	1,115
Loans:
Ending balance	63,148	88,537	82,660
Ending balance: individually evaluated for impairment	338	464
Ending balance: collectively evaluated for impairment	62,810	88,073
Ending balance: loans acquired with deteriorated credit quality	0	0
Lease financing receivable
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	5	14
Charge-offs	0	0
Recoveries	0	0
Provision	(1)	(5)
Ending balance	4	9
Ending balance: individually evaluated for impairment	1	0
Ending balance: collectively evaluated for impairment	3	9
Loans:
Ending balance	760	1,449	1,095
Ending balance: individually evaluated for impairment	34	0
Ending balance: collectively evaluated for impairment	726	1,449
Ending balance: loans acquired with deteriorated credit quality	0	0
Other
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	6	12
Charge-offs	0	0
Recoveries	0	0
Provision	18	10
Ending balance	24	22
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	24	22
Loans:
Ending balance	5,769	2,912	$ 767
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	5,769	2,912
Ending balance: loans acquired with deteriorated credit quality	$ 0	$ 0

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=27045933&loc=d3e13503-111538

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522

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