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, 2020	Dec. 31, 2019	Sep. 30, 2019
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	$ 4,374,517	$ 3,785,661	$ 3,831,090
Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	535,042	710,161
Loans and leases	521,120	691,341
Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	1,347,855	1,276,542	1,306,288
Commercial Real Estate | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	318,725	356,787
Loans and leases	310,879	348,365
Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	633,396	711,822	749,103
Residential Real Estate | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	91,947	130,412
Loans and leases	90,835	128,527
Construction, Land Development, and Other Land
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	239,034	278,657	280,999
Construction, Land Development, and Other Land | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	280	38,416
Loans and leases	213	37,490
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	1,328,809	1,331,565	1,302,162
Commercial and Industrial | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	107,558	159,599
Loans and leases	104,221	153,660
Installment and Other
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	3,143	6,565	9,354
Installment and Other | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	602	971
Loans and leases	583	944
Lease Financing Receivables
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	200,089	180,510	$ 183,184
Lease Financing Receivables | Acquired Non-impaired Loans and Leases
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	15,930	23,976
Loans and leases	$ 14,389	$ 22,355