Loans and Leases - Major Categories (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011		Sep. 30, 2011
Summary of major loan and lease categories
Total loans and leases held for investment, net of deferred income	$ 1,469,511	$ 1,446,406	[1]	$ 1,446,273
Unearned lease income	(11,040)	(9,965)
Net deferred costs	1,057	876
Overdraft deposits	122	123
Commercial, financial and agricultural [Member]
Summary of major loan and lease categories
Total loans and leases held for investment, net of deferred income	476,125	477,662
Real estate-commercial [Member]
Summary of major loan and lease categories
Total loans and leases held for investment, net of deferred income	515,743	514,953
Real estate-construction [Member]
Summary of major loan and lease categories
Total loans and leases held for investment, net of deferred income	95,245	90,397
Real estate-residential secured for business purpose [Member]
Summary of major loan and lease categories
Total loans and leases held for investment, net of deferred income	32,820	32,481
Real estate-residential secured for personal purpose [Member]
Summary of major loan and lease categories
Total loans and leases held for investment, net of deferred income	148,053	132,245
Real estate-home equity secured for personal purpose [Member]
Summary of major loan and lease categories
Total loans and leases held for investment, net of deferred income	82,337	80,478
Loans to individuals [Member]
Summary of major loan and lease categories
Total loans and leases held for investment, net of deferred income	42,626	44,965
Lease financings [Member]
Summary of major loan and lease categories
Total loans and leases held for investment, net of deferred income	$ 76,562	$ 73,225

[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.