Loans and the Allowance for Loan Losses - (Details 3) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Investment and interest income recognized on impaired loans
Average Recorded Investment	$ 32,192	$ 40,558
Interest Income Recognized	225	251
Receivables Acquired with Deteriorated Credit Quality
Investment and interest income recognized on impaired loans
Average Recorded Investment	374,716	359,618
Interest Income Recognized	4,165	4,193
Commercial, financial, agricultural
Investment and interest income recognized on impaired loans
Average Recorded Investment	326	950
Interest Income Recognized	2	7
Commercial, financial, agricultural | Receivables Acquired with Deteriorated Credit Quality
Investment and interest income recognized on impaired loans
Average Recorded Investment	18,024	25,978
Interest Income Recognized	327	233
Lease financing
Investment and interest income recognized on impaired loans
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Lease financing | Receivables Acquired with Deteriorated Credit Quality
Investment and interest income recognized on impaired loans
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Real estate – construction
Investment and interest income recognized on impaired loans
Average Recorded Investment	0	104
Interest Income Recognized	0	0
Real estate – construction | Receivables Acquired with Deteriorated Credit Quality
Investment and interest income recognized on impaired loans
Average Recorded Investment	2,608	0
Interest Income Recognized	25	0
Real estate – 1-4 family mortgage
Investment and interest income recognized on impaired loans
Average Recorded Investment	15,252	13,886
Interest Income Recognized	90	67
Real estate – 1-4 family mortgage | Receivables Acquired with Deteriorated Credit Quality
Investment and interest income recognized on impaired loans
Average Recorded Investment	101,089	86,713
Interest Income Recognized	953	1,043
Real estate – commercial mortgage
Investment and interest income recognized on impaired loans
Average Recorded Investment	16,547	25,618
Interest Income Recognized	132	177
Real estate – commercial mortgage | Receivables Acquired with Deteriorated Credit Quality
Investment and interest income recognized on impaired loans
Average Recorded Investment	250,041	242,712
Interest Income Recognized	2,831	2,871
Installment loans to individuals
Investment and interest income recognized on impaired loans
Average Recorded Investment	67	0
Interest Income Recognized	1	0
Installment loans to individuals | Receivables Acquired with Deteriorated Credit Quality
Investment and interest income recognized on impaired loans
Average Recorded Investment	2,954	4,215
Interest Income Recognized	$ 29	$ 46