Loans and the Allowance for Loan Losses - (Details 2) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Impaired loans
Unpaid Contractual Principal Balance	$ 36,514	$ 42,470
Recorded Investment With Allowance	31,624	36,615
Recorded Investment With No Allowance	0	12
Total Recorded Investment	31,624	36,627
Related Allowance	7,399	7,600
Receivables Acquired with Deteriorated Credit Quality
Impaired loans
Unpaid Contractual Principal Balance	416,912	430,511
Recorded Investment With Allowance	78,328	75,061
Recorded Investment With No Allowance	246,681	261,104
Total Recorded Investment	325,009	336,165
Related Allowance	2,022	1,706
Commercial, financial, agricultural
Impaired loans
Unpaid Contractual Principal Balance	328	1,308
Recorded Investment With Allowance	321	358
Recorded Investment With No Allowance	0	12
Total Recorded Investment	321	370
Related Allowance	6	6
Commercial, financial, agricultural | Receivables Acquired with Deteriorated Credit Quality
Impaired loans
Unpaid Contractual Principal Balance	24,323	27,049
Recorded Investment With Allowance	4,807	5,197
Recorded Investment With No Allowance	9,643	11,292
Total Recorded Investment	14,450	16,489
Related Allowance	422	353
Lease financing
Impaired loans
Unpaid Contractual Principal Balance	0	0
Recorded Investment With Allowance	0	0
Recorded Investment With No Allowance	0	0
Total Recorded Investment	0	0
Related Allowance	0	0
Lease financing | Receivables Acquired with Deteriorated Credit Quality
Impaired loans
Unpaid Contractual Principal Balance	0	0
Recorded Investment With Allowance	0	0
Recorded Investment With No Allowance	0	0
Total Recorded Investment	0	0
Related Allowance	0	0
Real estate – construction
Impaired loans
Unpaid Contractual Principal Balance	0	2,710
Recorded Investment With Allowance	0	2,698
Recorded Investment With No Allowance	0	0
Total Recorded Investment	0	2,698
Related Allowance	0	20
Real estate – construction | Receivables Acquired with Deteriorated Credit Quality
Impaired loans
Unpaid Contractual Principal Balance	2,635	2,916
Recorded Investment With Allowance	0	0
Recorded Investment With No Allowance	2,504	2,749
Total Recorded Investment	2,504	2,749
Related Allowance	0	0
Real estate – 1-4 family mortgage
Impaired loans
Unpaid Contractual Principal Balance	16,052	18,193
Recorded Investment With Allowance	14,786	16,650
Recorded Investment With No Allowance	0	0
Total Recorded Investment	14,786	16,650
Related Allowance	4,311	4,475
Real estate – 1-4 family mortgage | Receivables Acquired with Deteriorated Credit Quality
Impaired loans
Unpaid Contractual Principal Balance	107,167	109,293
Recorded Investment With Allowance	16,573	15,702
Recorded Investment With No Allowance	72,391	75,947
Total Recorded Investment	88,964	91,649
Related Allowance	335	256
Real estate – commercial mortgage
Impaired loans
Unpaid Contractual Principal Balance	20,067	20,169
Recorded Investment With Allowance	16,450	16,819
Recorded Investment With No Allowance	0	0
Total Recorded Investment	16,450	16,819
Related Allowance	3,082	3,099
Real estate – commercial mortgage | Receivables Acquired with Deteriorated Credit Quality
Impaired loans
Unpaid Contractual Principal Balance	279,548	287,821
Recorded Investment With Allowance	56,555	53,762
Recorded Investment With No Allowance	160,034	168,848
Total Recorded Investment	216,589	222,610
Related Allowance	1,264	1,096
Installment loans to individuals
Impaired loans
Unpaid Contractual Principal Balance	67	90
Recorded Investment With Allowance	67	90
Recorded Investment With No Allowance	0	0
Total Recorded Investment	67	90
Related Allowance	0	0
Installment loans to individuals | Receivables Acquired with Deteriorated Credit Quality
Impaired loans
Unpaid Contractual Principal Balance	3,239	3,432
Recorded Investment With Allowance	393	400
Recorded Investment With No Allowance	2,109	2,268
Total Recorded Investment	2,502	2,668
Related Allowance	$ 1	$ 1