Loans and the Allowance for Loan Losses (Details 7) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Loan portfolio not subject to risk rating
Loan portfolio	$ 1,351,624	$ 1,032,128
Commercial, financial, agricultural [Member]
Loan portfolio not subject to risk rating
Loan portfolio	82,447	74,213
Lease financing [Member]
Loan portfolio not subject to risk rating
Loan portfolio	75	195
Real estate - construction [Member]
Loan portfolio not subject to risk rating
Loan portfolio	41,045	31,774
Real estate - 1-4 family mortgage [Member]
Loan portfolio not subject to risk rating
Loan portfolio	912,733	675,402
Real estate - commercial mortgage [Member]
Loan portfolio not subject to risk rating
Loan portfolio	227,841	195,535
Installment loans to individuals [Member]
Loan portfolio not subject to risk rating
Loan portfolio	87,483	55,009
Performing [Member]
Loan portfolio not subject to risk rating
Loan portfolio	1,348,435	1,026,050
Performing [Member] | Commercial, financial, agricultural [Member]
Loan portfolio not subject to risk rating
Loan portfolio	82,283	74,003
Performing [Member] | Lease financing [Member]
Loan portfolio not subject to risk rating
Loan portfolio	75	195
Performing [Member] | Real estate - construction [Member]
Loan portfolio not subject to risk rating
Loan portfolio	41,045	31,774
Performing [Member] | Real estate - 1-4 family mortgage [Member]
Loan portfolio not subject to risk rating
Loan portfolio	910,066	670,074
Performing [Member] | Real estate - commercial mortgage [Member]
Loan portfolio not subject to risk rating
Loan portfolio	227,578	195,086
Performing [Member] | Installment loans to individuals [Member]
Loan portfolio not subject to risk rating
Loan portfolio	87,388	54,918
Non-Performing [Member]
Loan portfolio not subject to risk rating
Loan portfolio	3,189	6,078
Non-Performing [Member] | Commercial, financial, agricultural [Member]
Loan portfolio not subject to risk rating
Loan portfolio	164	210
Non-Performing [Member] | Lease financing [Member]
Loan portfolio not subject to risk rating
Loan portfolio	0	0
Non-Performing [Member] | Real estate - construction [Member]
Loan portfolio not subject to risk rating
Loan portfolio	0	0
Non-Performing [Member] | Real estate - 1-4 family mortgage [Member]
Loan portfolio not subject to risk rating
Loan portfolio	2,667	5,328
Non-Performing [Member] | Real estate - commercial mortgage [Member]
Loan portfolio not subject to risk rating
Loan portfolio	263	449
Non-Performing [Member] | Installment loans to individuals [Member]
Loan portfolio not subject to risk rating
Loan portfolio	$ 95	$ 91