Loans and Leases - Major Categories (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012		Mar. 31, 2012
Summary of Major Loan and Lease Categories
Total loans and leases held for investment, net of deferred income	$ 1,487,375	$ 1,481,862	[1]	$ 1,459,830
Unearned lease income	(12,816)	(12,355)
Net deferred costs (fees)	1,648	1,432
Overdraft deposits	135	128
Commercial, financial and agricultural [Member]
Summary of Major Loan and Lease Categories
Total loans and leases held for investment, net of deferred income	468,437	468,421
Real estate-commercial [Member]
Summary of Major Loan and Lease Categories
Total loans and leases held for investment, net of deferred income	551,761	530,122
Real estate-construction [Member]
Summary of Major Loan and Lease Categories
Total loans and leases held for investment, net of deferred income	79,285	91,250
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	31,755	35,179
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	143,487	146,526
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	83,399	82,727
Loans to individuals [Member]
Summary of Major Loan and Lease Categories
Total loans and leases held for investment, net of deferred income	41,781	43,780
Lease financings [Member]
Summary of Major Loan and Lease Categories
Total loans and leases held for investment, net of deferred income	$ 87,470	$ 83,857

[1] Note: The consolidated balance sheet at December 31, 2012 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. See accompanying notes to the unaudited consolidated financial statements.