Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Summary of Contractual Delinquency Information (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	$ 4,374,517	$ 3,785,661	$ 3,831,090
Commercial Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	1,347,855	1,276,542	1,306,288
Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	633,396	711,822	749,103
Construction, Land Development, and Other Land
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	239,034	278,657	280,999
Commercial and Industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	1,328,809	1,331,565	1,302,162
Paycheck Protection Program ("PPP")
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	622,191
Installment and Other
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	3,143	6,565	9,354
Lease Financing Receivables
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	200,089	180,510	$ 183,184
Acquired Non-Impaired and Originated Loans
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	53,182	76,436
Non-accrual	43,196	36,272
Current	4,104,517	3,450,557
Total loans and leases	4,157,699	3,526,993
Acquired Non-Impaired and Originated Loans | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	7,672	25,963
Acquired Non-Impaired and Originated Loans | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	2,314	14,201
Acquired Non-Impaired and Originated Loans | Commercial Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	21,807	31,696
Non-accrual	21,067	12,274
Current	1,208,934	1,108,932
Total loans and leases	1,230,741	1,140,628
Acquired Non-Impaired and Originated Loans | Commercial Real Estate | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	282	14,269
Acquired Non-Impaired and Originated Loans | Commercial Real Estate | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	458	5,153
Acquired Non-Impaired and Originated Loans | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	3,855	5,018
Non-accrual	1,843	1,371
Current	545,344	606,581
Total loans and leases	549,199	611,599
Acquired Non-Impaired and Originated Loans | Residential Real Estate | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	1,038	3,187
Acquired Non-Impaired and Originated Loans | Residential Real Estate | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	974	460
Acquired Non-Impaired and Originated Loans | Construction, Land Development, and Other Land
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	2,035	4,460
Current	232,195	268,824
Total loans and leases	234,230	273,284
Acquired Non-Impaired and Originated Loans | Construction, Land Development, and Other Land | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	2,035
Acquired Non-Impaired and Originated Loans | Construction, Land Development, and Other Land | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		4,460
Acquired Non-Impaired and Originated Loans | Commercial and Industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	22,571	33,534
Non-accrual	19,048	22,151
Current	1,295,749	1,281,122
Total loans and leases	1,318,320	1,314,656
Acquired Non-Impaired and Originated Loans | Commercial and Industrial | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	3,417	7,789
Acquired Non-Impaired and Originated Loans | Commercial and Industrial | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	106	3,594
Acquired Non-Impaired and Originated Loans | Paycheck Protection Program ("PPP")
Financing Receivable Recorded Investment Past Due [Line Items]
Current	622,191
Total loans and leases	622,191
Acquired Non-Impaired and Originated Loans | Installment and Other
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	8	136
Non-accrual	1	1
Current	2,921	6,180
Total loans and leases	2,929	6,316
Acquired Non-Impaired and Originated Loans | Installment and Other | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	7	133
Acquired Non-Impaired and Originated Loans | Installment and Other | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		2
Acquired Non-Impaired and Originated Loans | Lease Financing Receivables
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	2,906	1,592
Non-accrual	1,237	475
Current	197,183	178,918
Total loans and leases	200,089	180,510
Acquired Non-Impaired and Originated Loans | Lease Financing Receivables | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	893	585
Acquired Non-Impaired and Originated Loans | Lease Financing Receivables | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	$ 776	$ 532