Loans and Leases - Age Analysis of Past Due Loans and Leases (Details 1) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012		Mar. 31, 2012
Age Analysis of Past Due Loans and Leases
30-59 Days Past Due	$ 10,574	$ 7,003
60-89 Days Past Due	1,052	699
Greater Than 90 Days Past Due	366	441
Total Past Due	11,992	8,143
Current	1,433,459	1,428,130
Total Loans and Leases Held for Investment	1,487,375	1,481,862	[1]	1,459,830
Recorded Investment Greater than 90 Days Past Due and Accruing Interest	366	441
Commercial, financial and agricultural [Member]
Age Analysis of Past Due Loans and Leases
30-59 Days Past Due	2,587	416
60-89 Days Past Due	22	95
Greater Than 90 Days Past Due	49
Total Past Due	2,658	511
Current	463,482	464,588
Total Loans and Leases Held for Investment	468,437	468,421
Recorded Investment Greater than 90 Days Past Due and Accruing Interest	49
Real estate-commercial [Member]
Age Analysis of Past Due Loans and Leases
30-59 Days Past Due	2,475	1,173
60-89 Days Past Due	230
Greater Than 90 Days Past Due
Total Past Due	2,705	1,173
Current	526,611	504,086
Total Loans and Leases Held for Investment	551,761	530,122
Recorded Investment Greater than 90 Days Past Due and Accruing Interest
Real estate-construction [Member]
Age Analysis of Past Due Loans and Leases
30-59 Days Past Due		306
60-89 Days Past Due
Greater Than 90 Days Past Due
Total Past Due		306
Current	63,521	74,959
Total Loans and Leases Held for Investment	79,285	91,250
Recorded Investment Greater than 90 Days Past Due and Accruing Interest
Real estate-residential secured for business purpose [Member]
Age Analysis of Past Due Loans and Leases
30-59 Days Past Due	1,970	1,663
60-89 Days Past Due
Greater Than 90 Days Past Due
Total Past Due	1,970	1,663
Current	29,614	33,344
Total Loans and Leases Held for Investment	31,755	35,179
Recorded Investment Greater than 90 Days Past Due and Accruing Interest
Real estate-residential secured for personal purpose [Member]
Age Analysis of Past Due Loans and Leases
30-59 Days Past Due	1,783	1,617
60-89 Days Past Due	70	152
Greater Than 90 Days Past Due
Total Past Due	1,853	1,769
Current	140,830	143,953
Total Loans and Leases Held for Investment	143,487	146,526
Recorded Investment Greater than 90 Days Past Due and Accruing Interest
Real estate-home equity secured for personal purpose [Member]
Age Analysis of Past Due Loans and Leases
30-59 Days Past Due	395	276
60-89 Days Past Due	64	64
Greater Than 90 Days Past Due		54
Total Past Due	459	394
Current	82,917	82,333
Total Loans and Leases Held for Investment	83,399	82,727
Recorded Investment Greater than 90 Days Past Due and Accruing Interest		54
Loans to individuals [Member]
Age Analysis of Past Due Loans and Leases
30-59 Days Past Due	366	551
60-89 Days Past Due	177	115
Greater Than 90 Days Past Due	223	347
Total Past Due	766	1,013
Current	40,974	42,729
Total Loans and Leases Held for Investment	41,781	43,780
Recorded Investment Greater than 90 Days Past Due and Accruing Interest	223	347
Lease financings [Member]
Age Analysis of Past Due Loans and Leases
30-59 Days Past Due	998	1,001
60-89 Days Past Due	489	273
Greater Than 90 Days Past Due	94	40
Total Past Due	1,581	1,314
Current	85,510	82,138
Total Loans and Leases Held for Investment	87,470	83,857
Recorded Investment Greater than 90 Days Past Due and Accruing Interest	$ 94	$ 40

[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.