Loans and Leases - Summary of Major Loan and Lease Categories (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	$ 3,835,228	$ 3,629,198
Total Loans and Leases Held for Investment, Acquired	332,676	377,376
Total Loans and Leases Held for Investment	4,167,904	4,006,574	$ 3,818,398
Imputed interest on lease financings, originated	(15,415)	(15,118)
Imputed interest of lease financings, acquired	0	0
Imputed interest on lease financings, included in the above table	(15,415)	(15,118)
Net deferred costs, Originated	4,701	3,930
Net deferred costs, Acquired	0	0
Net deferred costs, included in the above table	4,701	3,930
Overdraft Deposits, Originated	127	139
Overdraft Deposits, Acquired	0	0
Overdraft deposits included in the above table	127	139
Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	921,182	913,166
Total Loans and Leases Held for Investment, Acquired	15,967	24,519
Total Loans and Leases Held for Investment	937,149	937,685	926,160
Real Estate-Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	1,650,052	1,507,579
Total Loans and Leases Held for Investment, Acquired	212,095	233,625
Total Loans and Leases Held for Investment	1,862,147	1,741,204
Real Estate-Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	230,459	215,513
Total Loans and Leases Held for Investment, Acquired	0	0
Total Loans and Leases Held for Investment	230,459	215,513
Real Estate-Residential Secured for Business Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	314,629	302,393
Total Loans and Leases Held for Investment, Acquired	51,011	60,403
Total Loans and Leases Held for Investment	365,640	362,796	338,712
Real Estate Residential Secured For Personal Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	373,792	338,451
Total Loans and Leases Held for Investment, Acquired	46,017	49,959
Total Loans and Leases Held for Investment	419,809	388,410
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	170,482	177,523
Total Loans and Leases Held for Investment, Acquired	7,446	8,728
Total Loans and Leases Held for Investment	177,928	186,251
Loans to Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	32,345	32,617
Total Loans and Leases Held for Investment, Acquired	140	142
Total Loans and Leases Held for Investment	32,485	32,759	31,191
Lease Financings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases Held for Investment, Originated	142,287	141,956
Total Loans and Leases Held for Investment, Acquired	0	0
Total Loans and Leases Held for Investment	$ 142,287	$ 141,956	$ 133,122