Loans and the Allowance for Loan Losses - (Details 8) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Loans acquired with deteriorated credit quality
Covered Loans	$ 30,533	$ 93,142
Total	6,059,309	5,371,025
Receivables Acquired with Deteriorated Credit Quality
Loans acquired with deteriorated credit quality
Covered Loans	23,344	66,973
Not Covered Loans	274,265	269,192
Total	297,609	336,165
Receivables Acquired with Deteriorated Credit Quality | Commercial Residential Mortgage [Member]
Loans acquired with deteriorated credit quality
Covered Loans	120	33,726
Not Covered Loans	200,880	188,884
Total	201,000	222,610
Receivables Acquired with Deteriorated Credit Quality | Commercial, financial, agricultural
Loans acquired with deteriorated credit quality
Covered Loans	14	1,759
Not Covered Loans	12,480	14,730
Total	12,494	16,489
Receivables Acquired with Deteriorated Credit Quality | Lease financing
Loans acquired with deteriorated credit quality
Covered Loans	0	0
Not Covered Loans	0	0
Total	0	0
Receivables Acquired with Deteriorated Credit Quality | Real estate – construction
Loans acquired with deteriorated credit quality
Covered Loans	0	91
Not Covered Loans	1,722	2,658
Total	1,722	2,749
Receivables Acquired with Deteriorated Credit Quality | Real estate – 1-4 family mortgage
Loans acquired with deteriorated credit quality
Covered Loans	23,190	31,354
Not Covered Loans	57,042	60,295
Total	80,232	91,649
Receivables Acquired with Deteriorated Credit Quality | Installment loans to individuals
Loans acquired with deteriorated credit quality
Covered Loans	20	43
Not Covered Loans	2,141	2,625
Total	$ 2,161	$ 2,668