Loans and Leases - Average Recorded Investment and Analysis of Interest on Impaired Loans (Details 7) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Average recorded investment in impaired loans and an analysis of interest on impaired loans
Average Recorded Investment	$ 43,725	$ 42,331
Interest Income Recognized	192	63
Interest Income That Would Have Been Recognized Under Original Terms	463	558
Commercial, financial and agricultural [Member]
Average recorded investment in impaired loans and an analysis of interest on impaired loans
Average Recorded Investment	2,884	5,337
Interest Income Recognized	8	2
Interest Income That Would Have Been Recognized Under Original Terms	39	92
Real estate-commercial real estate [Member]
Average recorded investment in impaired loans and an analysis of interest on impaired loans
Average Recorded Investment	23,958	20,814
Interest Income Recognized	155	43
Interest Income That Would Have Been Recognized Under Original Terms	225	269
Real estate-construction [Member]
Average recorded investment in impaired loans and an analysis of interest on impaired loans
Average Recorded Investment	15,844	15,956
Interest Income Recognized	28	17
Interest Income That Would Have Been Recognized Under Original Terms	184	195
Real estate-residential secured for business purpose [Member]
Average recorded investment in impaired loans and an analysis of interest on impaired loans
Average Recorded Investment	184	110
Interest Income Recognized
Interest Income That Would Have Been Recognized Under Original Terms	3	1
Real estate-residential secured for personal purpose [Member]
Average recorded investment in impaired loans and an analysis of interest on impaired loans
Average Recorded Investment	803	57
Interest Income Recognized
Interest Income That Would Have Been Recognized Under Original Terms	12	1
Real estate-home equity secured for personal purpose [Member]
Average recorded investment in impaired loans and an analysis of interest on impaired loans
Average Recorded Investment	6	7
Interest Income Recognized
Interest Income That Would Have Been Recognized Under Original Terms
Loans to individuals [Member]
Average recorded investment in impaired loans and an analysis of interest on impaired loans
Average Recorded Investment	46	50
Interest Income Recognized	1	1
Interest Income That Would Have Been Recognized Under Original Terms