Loans and Leases - Summary of Major Loan and Lease Categories (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	$ 2,890,981	$ 2,390,832
Total Loans and Leases Held for Investment, Acquired	596,183	895,054
Total Loans and Leases Held for Investment	3,487,164	3,285,886	$ 3,190,361
Unearned Lease Income, Originated	(13,864)	(15,970)
Unearned Lease Income, Acquired	0	0
Unearned lease income, included in the above table	(13,864)	(15,970)
Net deferred costs, Originated	4,725	4,503
Net deferred costs, Acquired	0	0
Net deferred costs, included in the above table	4,725	4,503
Overdraft Deposits, Originated	68	84
Overdraft Deposits, Acquired	0	0
Overdraft deposits included in the above table	68	84
Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	782,769	663,221
Total Loans and Leases Held for Investment, Acquired	76,448	160,045
Total Loans and Leases Held for Investment	859,217	823,266	783,680
Real Estate-Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	1,176,956	909,581
Total Loans and Leases Held for Investment, Acquired	339,018	465,368
Total Loans and Leases Held for Investment	1,515,974	1,374,949
Real Estate-Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	149,917	142,891
Total Loans and Leases Held for Investment, Acquired	6,156	31,953
Total Loans and Leases Held for Investment	156,073	174,844
Real Estate-Residential Secured for Business Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	213,811	151,931
Total Loans and Leases Held for Investment, Acquired	96,209	142,137
Total Loans and Leases Held for Investment	310,020	294,068	288,194
Real Estate Residential Secured For Personal Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	249,283	210,377
Total Loans and Leases Held for Investment, Acquired	66,623	80,431
Total Loans and Leases Held for Investment	315,906	290,808
Real Estate-Home Equity Secured for Personal Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	166,810	147,982
Total Loans and Leases Held for Investment, Acquired	11,585	14,857
Total Loans and Leases Held for Investment	178,395	162,839
Loans to Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	27,297	30,110
Total Loans and Leases Held for Investment, Acquired	144	263
Total Loans and Leases Held for Investment	27,441	30,373	30,649
Lease Financings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	124,138	134,739
Total Loans and Leases Held for Investment, Acquired	0	0
Total Loans and Leases Held for Investment	$ 124,138	$ 134,739	$ 129,885