Loans and Leases - Major Categories (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011		Jun. 30, 2011
Summary of major loan and lease categories
Total loans and leases, net of deferred income	$ 1,465,449	$ 1,446,406	[1]	$ 1,438,707
Unearned lease income	(10,768)	(9,965)
Net deferred costs	897	876
Overdraft deposits	103	123
Commercial, financial and agricultural [Member]
Summary of major loan and lease categories
Total loans and leases, net of deferred income	497,955	484,687
Real estate-commercial [Member]
Summary of major loan and lease categories
Total loans and leases, net of deferred income	517,282	514,953
Real estate-construction [Member]
Summary of major loan and lease categories
Total loans and leases, net of deferred income	79,910	90,397
Real estate-residential secured for business purpose [Member]
Summary of major loan and lease categories
Total loans and leases, net of deferred income	32,097	32,481
Real estate-residential secured for personal purpose [Member]
Summary of major loan and lease categories
Total loans and leases, net of deferred income	140,217	125,220
Real estate-home equity secured for personal purpose [Member]
Summary of major loan and lease categories
Total loans and leases, net of deferred income	78,696	80,478
Loans to individuals [Member]
Summary of major loan and lease categories
Total loans and leases, net of deferred income	44,037	44,965
Lease Financings [Member]
Summary of major loan and lease categories
Total loans and leases, net of deferred income	$ 75,255	$ 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.