Loans and the Allowance for Loan Losses (Details 6) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Loan portfolio not subject to risk rating
Loan portfolio	$ 2,011,292	$ 1,551,189
Performing
Loan portfolio not subject to risk rating
Loan portfolio	2,007,361	1,546,689
Non-Performing
Loan portfolio not subject to risk rating
Loan portfolio	3,931	4,500
Commercial, financial, agricultural
Loan portfolio not subject to risk rating
Loan portfolio	144,931	115,175
Commercial, financial, agricultural | Performing
Loan portfolio not subject to risk rating
Loan portfolio	144,838	114,996
Commercial, financial, agricultural | Non-Performing
Loan portfolio not subject to risk rating
Loan portfolio	93	179
Lease financing
Loan portfolio not subject to risk rating
Loan portfolio	34,815	10,114
Lease financing | Performing
Loan portfolio not subject to risk rating
Loan portfolio	34,815	10,114
Lease financing | Non-Performing
Loan portfolio not subject to risk rating
Loan portfolio	0	0
Real estate – construction
Loan portfolio not subject to risk rating
Loan portfolio	81,035	60,523
Real estate – construction | Performing
Loan portfolio not subject to risk rating
Loan portfolio	81,035	60,323
Real estate – construction | Non-Performing
Loan portfolio not subject to risk rating
Loan portfolio	0	200
Real estate – 1-4 family mortgage
Loan portfolio not subject to risk rating
Loan portfolio	1,343,233	1,013,375
Real estate – 1-4 family mortgage | Performing
Loan portfolio not subject to risk rating
Loan portfolio	1,340,356	1,010,645
Real estate – 1-4 family mortgage | Non-Performing
Loan portfolio not subject to risk rating
Loan portfolio	2,877	2,730
Real estate – commercial mortgage
Loan portfolio not subject to risk rating
Loan portfolio	294,909	268,219
Real estate – commercial mortgage | Performing
Loan portfolio not subject to risk rating
Loan portfolio	294,042	266,867
Real estate – commercial mortgage | Non-Performing
Loan portfolio not subject to risk rating
Loan portfolio	867	1,352
Installment loans to individuals
Loan portfolio not subject to risk rating
Loan portfolio	112,369	83,783
Installment loans to individuals | Performing
Loan portfolio not subject to risk rating
Loan portfolio	112,275	83,744
Installment loans to individuals | Non-Performing
Loan portfolio not subject to risk rating
Loan portfolio	$ 94	$ 39