Loans and Allowance for Loan Losses - Schedule of Accounts Notes Loans and Financial Receivables (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Finance Receivable Transferred To Held For Sale [Line Items]
Loans and deferred loan fees receivables	$ 1,450,635	$ 1,332,086
Allowance for loan losses	23,593	35,156
Loans, net	1,427,042	1,296,930
Commercial, financial & agricultural [Member]
Finance Receivable Transferred To Held For Sale [Line Items]
Loans and deferred loan fees receivables	174,217	142,960
Real estate - construction & development [Member]
Finance Receivable Transferred To Held For Sale [Line Items]
Loans and deferred loan fees receivables	114,199	130,270
Real estate - commercial and farmland [Member]
Finance Receivable Transferred To Held For Sale [Line Items]
Loans and deferred loan fees receivables	732,322	672,765
Real estate - residential [Member]
Finance Receivable Transferred To Held For Sale [Line Items]
Loans and deferred loan fees receivables	346,480	330,727
Consumer installment loans [Member]
Finance Receivable Transferred To Held For Sale [Line Items]
Loans and deferred loan fees receivables	40,178	37,296
Other Loans [Member]
Finance Receivable Transferred To Held For Sale [Line Items]
Loans and deferred loan fees receivables	$ 43,239	$ 18,068

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 8, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph a(ii)

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 114

-Paragraph 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details

- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References+ Details