Loan and Lease Receivables - Schedule of Unpaid Principal Balance and Carrying Value for Acquired Non-impaired Loans and Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	$ 3,831,090	$ 3,501,626	$ 3,455,802
Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	806,088	1,018,921
Loans and leases	784,611	986,286
Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	1,306,288	1,261,607	1,272,204
Commercial Real Estate | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	400,422	473,262
Loans and leases	391,294	462,565
Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	749,103	704,902	705,196
Residential Real Estate | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	144,075	127,478
Loans and leases	141,855	124,659
Construction, Land Development, and Other Land
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	280,999	185,349	181,705
Construction, Land Development, and Other Land | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	40,778	38,494
Loans and leases	39,657	37,442
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	1,302,162	1,144,797	1,095,446
Commercial and Industrial | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	194,756	344,879
Loans and leases	187,413	328,672
Installment and Other
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	9,354	13,718	12,194
Installment and Other | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	1,303	1,831
Loans and leases	1,269	1,596
Lease Financing Receivables
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	183,184	191,253	$ 189,057
Lease Financing Receivables | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	24,754	32,977
Loans and leases	$ 23,123	$ 31,352