Loans and Leases - Credit Quality Indicators (Details 3) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011		Sep. 30, 2011
Credit Quality Indicators
Loans and leases held for investment	$ 1,469,511	$ 1,446,406	[1]	$ 1,446,273
Commercial, financial and agricultural [Member]
Credit Quality Indicators
Loans and leases held for investment	476,125	477,662
Real estate-commercial [Member]
Credit Quality Indicators
Loans and leases held for investment	515,743	514,953
Real estate-construction [Member]
Credit Quality Indicators
Loans and leases held for investment	95,245	90,397
Real estate-residential secured for business purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	32,820	32,481
Real estate-residential secured for personal purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	148,053	132,245
Real estate-home equity secured for personal purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	82,337	80,478
Loans to individuals [Member]
Credit Quality Indicators
Loans and leases held for investment	42,626	44,965
Lease financings [Member]
Credit Quality Indicators
Loans and leases held for investment	76,562	73,225
Grade:1. Cash Secured / 2. Fully Secured [Member] | Commercial, financial and agricultural [Member]
Credit Quality Indicators
Loans and leases held for investment	2,125	2,426
Grade:1. Cash Secured / 2. Fully Secured [Member] | Real estate-commercial [Member]
Credit Quality Indicators
Loans and leases held for investment
Grade:1. Cash Secured / 2. Fully Secured [Member] | Real estate-construction [Member]
Credit Quality Indicators
Loans and leases held for investment
Grade:1. Cash Secured / 2. Fully Secured [Member] | Real estate-residential secured for business purpose [Member]
Credit Quality Indicators
Loans and leases held for investment
Grade:3. Strong [Member] | Commercial, financial and agricultural [Member]
Credit Quality Indicators
Loans and leases held for investment	4,387	4,441
Grade:3. Strong [Member] | Real estate-commercial [Member]
Credit Quality Indicators
Loans and leases held for investment	9,347	9,365
Grade:3. Strong [Member] | Real estate-construction [Member]
Credit Quality Indicators
Loans and leases held for investment	485	1,124
Grade:3. Strong [Member] | Real estate-residential secured for business purpose [Member]
Credit Quality Indicators
Loans and leases held for investment
Grade:4. Satisfactory [Member] | Commercial, financial and agricultural [Member]
Credit Quality Indicators
Loans and leases held for investment	41,583	32,730
Grade:4. Satisfactory [Member] | Real estate-commercial [Member]
Credit Quality Indicators
Loans and leases held for investment	22,595	28,517
Grade:4. Satisfactory [Member] | Real estate-construction [Member]
Credit Quality Indicators
Loans and leases held for investment	3,121	89
Grade:4. Satisfactory [Member] | Real estate-residential secured for business purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	342	1,309
Grade:5. Acceptable [Member] | Commercial, financial and agricultural [Member]
Credit Quality Indicators
Loans and leases held for investment	272,942	289,835
Grade:5. Acceptable [Member] | Real estate-commercial [Member]
Credit Quality Indicators
Loans and leases held for investment	285,506	296,499
Grade:5. Acceptable [Member] | Real estate-construction [Member]
Credit Quality Indicators
Loans and leases held for investment	31,994	35,207
Grade:5. Acceptable [Member] | Real estate-residential secured for business purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	19,411	18,990
Grade:6. Pre-watch [Member] | Commercial, financial and agricultural [Member]
Credit Quality Indicators
Loans and leases held for investment	92,646	79,402
Grade:6. Pre-watch [Member] | Real estate-commercial [Member]
Credit Quality Indicators
Loans and leases held for investment	126,515	100,581
Grade:6. Pre-watch [Member] | Real estate-construction [Member]
Credit Quality Indicators
Loans and leases held for investment	42,429	33,993
Grade:6. Pre-watch [Member] | Real estate-residential secured for business purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	10,146	8,853
Grade:7. Special Mention [Member] | Commercial, financial and agricultural [Member]
Credit Quality Indicators
Loans and leases held for investment	33,580	26,162
Grade:7. Special Mention [Member] | Real estate-commercial [Member]
Credit Quality Indicators
Loans and leases held for investment	28,161	29,055
Grade:7. Special Mention [Member] | Real estate-construction [Member]
Credit Quality Indicators
Loans and leases held for investment	477	1,715
Grade:7. Special Mention [Member] | Real estate-residential secured for business purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	288	663
Grade:8. Substandard [Member] | Commercial, financial and agricultural [Member]
Credit Quality Indicators
Loans and leases held for investment	27,289	40,634
Grade:8. Substandard [Member] | Real estate-commercial [Member]
Credit Quality Indicators
Loans and leases held for investment	42,626	49,943
Grade:8. Substandard [Member] | Real estate-construction [Member]
Credit Quality Indicators
Loans and leases held for investment	16,739	18,269
Grade:8. Substandard [Member] | Real estate-residential secured for business purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	2,633	2,666
Grade:9. Doubtful [Member] | Commercial, financial and agricultural [Member]
Credit Quality Indicators
Loans and leases held for investment	1,573	2,032
Grade:9. Doubtful [Member] | Real estate-commercial [Member]
Credit Quality Indicators
Loans and leases held for investment	993	993
Grade:9. Doubtful [Member] | Real estate-construction [Member]
Credit Quality Indicators
Loans and leases held for investment
Grade:9. Doubtful [Member] | Real estate-residential secured for business purpose [Member]
Credit Quality Indicators
Loans and leases held for investment
Grade:10. Loss [Member] | Commercial, financial and agricultural [Member]
Credit Quality Indicators
Loans and leases held for investment
Grade:10. Loss [Member] | Real estate-commercial [Member]
Credit Quality Indicators
Loans and leases held for investment
Grade:10. Loss [Member] | Real estate-construction [Member]
Credit Quality Indicators
Loans and leases held for investment
Grade:10. Loss [Member] | Real estate-residential secured for business purpose [Member]
Credit Quality Indicators
Loans and leases held for investment
Performing Financing Receivable [Member] | Real estate-residential secured for personal purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	147,730	132,188
Performing Financing Receivable [Member] | Real estate-home equity secured for personal purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	82,279	80,334
Performing Financing Receivable [Member] | Loans to individuals [Member]
Credit Quality Indicators
Loans and leases held for investment	42,289	44,711
Performing Financing Receivable [Member] | Lease financings [Member]
Credit Quality Indicators
Loans and leases held for investment	75,985	72,282
Nonperforming Financing Receivable [Member] | Real estate-residential secured for personal purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	323	57
Nonperforming Financing Receivable [Member] | Real estate-home equity secured for personal purpose [Member]
Credit Quality Indicators
Loans and leases held for investment	58	144
Nonperforming Financing Receivable [Member] | Loans to individuals [Member]
Credit Quality Indicators
Loans and leases held for investment	337	254
Nonperforming Financing Receivable [Member] | Lease financings [Member]
Credit Quality Indicators
Loans and leases held for investment	$ 577	$ 943

[1] Note: The consolidated balance sheet at December 31, 2011 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by U. S. generally accepted accounting principles for complete financial statements. Certain amounts have been reclassified to conform to the current-year presentation. See accompanying notes to the unaudited consolidated financial statements.