Loans and the Allowance for Loan Losses - (Details 7) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Loan portfolio not subject to risk rating
Total	$ 2,153,890	$ 2,011,292
Commercial, financial, agricultural
Loan portfolio not subject to risk rating
Total	154,110	144,931
Lease financing
Loan portfolio not subject to risk rating
Total	43,116	34,815
Real estate – construction
Loan portfolio not subject to risk rating
Total	88,692	81,035
Real estate – 1-4 family mortgage
Loan portfolio not subject to risk rating
Total	1,442,559	1,343,233
Real estate – commercial mortgage
Loan portfolio not subject to risk rating
Total	314,003	294,909
Installment loans to individuals
Loan portfolio not subject to risk rating
Total	111,410	112,369
Performing
Loan portfolio not subject to risk rating
Total	2,149,941	2,007,361
Performing | Commercial, financial, agricultural
Loan portfolio not subject to risk rating
Total	153,534	144,838
Performing | Lease financing
Loan portfolio not subject to risk rating
Total	43,116	34,815
Performing | Real estate – construction
Loan portfolio not subject to risk rating
Total	88,189	81,035
Performing | Real estate – 1-4 family mortgage
Loan portfolio not subject to risk rating
Total	1,440,427	1,340,356
Performing | Real estate – commercial mortgage
Loan portfolio not subject to risk rating
Total	313,543	294,042
Performing | Installment loans to individuals
Loan portfolio not subject to risk rating
Total	111,132	112,275
Non- Performing
Loan portfolio not subject to risk rating
Total	3,949	3,931
Non- Performing | Commercial, financial, agricultural
Loan portfolio not subject to risk rating
Total	576	93
Non- Performing | Lease financing
Loan portfolio not subject to risk rating
Total	0	0
Non- Performing | Real estate – construction
Loan portfolio not subject to risk rating
Total	503	0
Non- Performing | Real estate – 1-4 family mortgage
Loan portfolio not subject to risk rating
Total	2,132	2,877
Non- Performing | Real estate – commercial mortgage
Loan portfolio not subject to risk rating
Total	460	867
Non- Performing | Installment loans to individuals
Loan portfolio not subject to risk rating
Total	$ 278	$ 94