Loan and Lease Receivables - Schedule of Unpaid Principal Balance and Carrying Value for Acquired Non-impaired Loans and Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	$ 2,277,492	$ 2,148,011	$ 1,345,437
Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	399,601	481,369
Loans and leases	376,419	462,086
Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	891,693	796,344	533,695
Commercial Real Estate | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	221,710	259,055
Loans and leases	211,359	250,289
Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	577,218	610,738	484,335
Residential Real Estate | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	32,605	41,282
Loans and leases	32,085	40,853
Construction, Land Development, and Other Land
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	105,429	140,766	40,232
Construction, Land Development, and Other Land | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	1,926	14,619
Loans and leases	1,845	14,430
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	521,238	438,238	165,696
Commercial and Industrial | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	105,529	125,806
Loans and leases	94,731	115,677
Installment and Other
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	4,228	2,959	1,926
Installment and Other | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	355	402
Loans and leases	42	364
Lease Financing Receivables
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	177,686	158,966	$ 119,553
Lease Financing Receivables | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	37,476	40,205
Loans and leases	$ 36,357	$ 40,473