Loans and Allowance for Credit Losses - Summary of Amortized Cost Balance of Each of Loan Classes Disaggregated by Collateral Type and Origination Year (Detail) $ in Thousands	Dec. 31, 2020 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	$ 6,232,622
Amortized Cost Basis by Origination Year 2019	2,122,556
Amortized Cost Basis by Origination Year 2018	1,075,973
Amortized Cost Basis by Origination Year 2017	694,095
Amortized Cost Basis by Origination Year 2016	786,120
Amortized Cost Basis by Origination Year Prior to 2016	481,977
Amortized Cost - Revolving Loans	4,459,302
Amortized Cost - Revolving Loans Converted to Term Loans	251,006
Total Loans	16,103,651
Commercial and Industrial Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	3,194,475
Amortized Cost Basis by Origination Year 2019	690,983
Amortized Cost Basis by Origination Year 2018	473,926
Amortized Cost Basis by Origination Year 2017	188,818
Amortized Cost Basis by Origination Year 2016	180,740
Amortized Cost Basis by Origination Year Prior to 2016	70,015
Amortized Cost - Revolving Loans	2,263,079
Amortized Cost - Revolving Loans Converted to Term Loans	38
Total Loans	7,062,074
Commercial and Industrial Portfolio [Member] | Equipment/Accounts Receivable/Inventory [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	3,185,589
Amortized Cost Basis by Origination Year 2019	684,488
Amortized Cost Basis by Origination Year 2018	471,950
Amortized Cost Basis by Origination Year 2017	185,167
Amortized Cost Basis by Origination Year 2016	178,576
Amortized Cost Basis by Origination Year Prior to 2016	69,599
Amortized Cost - Revolving Loans	2,108,799
Total Loans	6,884,168
Commercial and Industrial Portfolio [Member] | Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	8,886
Amortized Cost Basis by Origination Year 2019	6,495
Amortized Cost Basis by Origination Year 2018	1,976
Amortized Cost Basis by Origination Year 2017	3,651
Amortized Cost Basis by Origination Year 2016	2,164
Amortized Cost Basis by Origination Year Prior to 2016	416
Amortized Cost - Revolving Loans	137,955
Amortized Cost - Revolving Loans Converted to Term Loans	38
Total Loans	161,581
Commercial and Industrial Portfolio [Member] | Overdrafts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost - Revolving Loans	16,325
Total Loans	16,325
Specialty Lending Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	64,258
Amortized Cost - Revolving Loans	447,042
Total Loans	511,300
Specialty Lending Portfolio [Member] | Asset-based [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	64,258
Amortized Cost - Revolving Loans	291,091
Total Loans	355,349
Specialty Lending Portfolio [Member] | Factoring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost - Revolving Loans	155,951
Total Loans	155,951
Commercial Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	1,934,548
Amortized Cost Basis by Origination Year 2019	1,085,218
Amortized Cost Basis by Origination Year 2018	499,245
Amortized Cost Basis by Origination Year 2017	410,603
Amortized Cost Basis by Origination Year 2016	522,903
Amortized Cost Basis by Origination Year Prior to 2016	330,646
Amortized Cost - Revolving Loans	874,808
Amortized Cost - Revolving Loans Converted to Term Loans	250,963
Total Loans	5,908,934
Commercial Real Estate Portfolio [Member] | Owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	579,212
Amortized Cost Basis by Origination Year 2019	334,098
Amortized Cost Basis by Origination Year 2018	233,192
Amortized Cost Basis by Origination Year 2017	170,913
Amortized Cost Basis by Origination Year 2016	120,603
Amortized Cost Basis by Origination Year Prior to 2016	176,377
Amortized Cost - Revolving Loans	18,880
Amortized Cost - Revolving Loans Converted to Term Loans	51,910
Total Loans	1,685,185
Commercial Real Estate Portfolio [Member] | Non-owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	846,030
Amortized Cost Basis by Origination Year 2019	630,457
Amortized Cost Basis by Origination Year 2018	230,549
Amortized Cost Basis by Origination Year 2017	169,193
Amortized Cost Basis by Origination Year 2016	333,215
Amortized Cost Basis by Origination Year Prior to 2016	115,753
Amortized Cost - Revolving Loans	49,384
Amortized Cost - Revolving Loans Converted to Term Loans	97,954
Total Loans	2,472,535
Commercial Real Estate Portfolio [Member] | Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	297,788
Amortized Cost Basis by Origination Year 2019	37,288
Amortized Cost Basis by Origination Year 2018	31,454
Amortized Cost Basis by Origination Year 2017	37,485
Amortized Cost Basis by Origination Year 2016	28,925
Amortized Cost Basis by Origination Year Prior to 2016	29,480
Amortized Cost - Revolving Loans	40,043
Total Loans	502,463
Commercial Real Estate Portfolio [Member] | 5+ Multi-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	190,922
Amortized Cost Basis by Origination Year 2019	80,293
Amortized Cost Basis by Origination Year 2018	2,835
Amortized Cost Basis by Origination Year 2017	32,498
Amortized Cost Basis by Origination Year 2016	39,802
Amortized Cost Basis by Origination Year Prior to 2016	6,298
Amortized Cost - Revolving Loans	2,418
Amortized Cost - Revolving Loans Converted to Term Loans	94,789
Total Loans	449,855
Commercial Real Estate Portfolio [Member] | 1-4 Family Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	144
Amortized Cost - Revolving Loans	30,131
Total Loans	30,275
Commercial Real Estate Portfolio [Member] | General Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	20,452
Amortized Cost Basis by Origination Year 2019	3,082
Amortized Cost Basis by Origination Year 2018	1,215
Amortized Cost Basis by Origination Year 2017	514
Amortized Cost Basis by Origination Year 2016	358
Amortized Cost Basis by Origination Year Prior to 2016	2,738
Amortized Cost - Revolving Loans	733,952
Amortized Cost - Revolving Loans Converted to Term Loans	6,310
Total Loans	768,621
Consumer Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	988,228
Amortized Cost Basis by Origination Year 2019	321,636
Amortized Cost Basis by Origination Year 2018	90,052
Amortized Cost Basis by Origination Year 2017	89,415
Amortized Cost Basis by Origination Year 2016	79,469
Amortized Cost Basis by Origination Year Prior to 2016	79,439
Amortized Cost - Revolving Loans	297,250
Amortized Cost - Revolving Loans Converted to Term Loans	5
Total Loans	1,945,494
Consumer Real Estate Portfolio [Member] | HELOC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	82,410
Amortized Cost Basis by Origination Year 2019	11,236
Amortized Cost Basis by Origination Year 2018	4,263
Amortized Cost Basis by Origination Year 2017	241
Amortized Cost Basis by Origination Year 2016	63
Amortized Cost Basis by Origination Year Prior to 2016	2,561
Amortized Cost - Revolving Loans	294,390
Amortized Cost - Revolving Loans Converted to Term Loans	5
Total Loans	395,169
Consumer Real Estate Portfolio [Member] | First Lien: 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	896,676
Amortized Cost Basis by Origination Year 2019	304,017
Amortized Cost Basis by Origination Year 2018	83,429
Amortized Cost Basis by Origination Year 2017	87,927
Amortized Cost Basis by Origination Year 2016	78,458
Amortized Cost Basis by Origination Year Prior to 2016	75,408
Amortized Cost - Revolving Loans	2,579
Total Loans	1,528,494
Consumer Real Estate Portfolio [Member] | Junior Lien: 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	9,142
Amortized Cost Basis by Origination Year 2019	6,383
Amortized Cost Basis by Origination Year 2018	2,360
Amortized Cost Basis by Origination Year 2017	1,247
Amortized Cost Basis by Origination Year 2016	948
Amortized Cost Basis by Origination Year Prior to 2016	1,470
Amortized Cost - Revolving Loans	281
Total Loans	21,831
Consumer Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	17,487
Amortized Cost Basis by Origination Year 2019	13,046
Amortized Cost Basis by Origination Year 2018	5,091
Amortized Cost Basis by Origination Year 2017	1,861
Amortized Cost Basis by Origination Year 2016	1,685
Amortized Cost Basis by Origination Year Prior to 2016	520
Amortized Cost - Revolving Loans	78,296
Total Loans	117,986
Consumer Portfolio [Member] | Revolving Line [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost - Revolving Loans	65,215
Total Loans	65,215
Consumer Portfolio [Member] | Auto [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	12,470
Amortized Cost Basis by Origination Year 2019	9,846
Amortized Cost Basis by Origination Year 2018	2,960
Amortized Cost Basis by Origination Year 2017	1,645
Amortized Cost Basis by Origination Year 2016	680
Amortized Cost Basis by Origination Year Prior to 2016	348
Total Loans	27,949
Consumer Portfolio [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	5,017
Amortized Cost Basis by Origination Year 2019	3,200
Amortized Cost Basis by Origination Year 2018	2,131
Amortized Cost Basis by Origination Year 2017	216
Amortized Cost Basis by Origination Year 2016	1,005
Amortized Cost Basis by Origination Year Prior to 2016	172
Amortized Cost - Revolving Loans	13,081
Total Loans	24,822
Credit Cards Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost - Revolving Loans	366,968
Total Loans	366,968
Credit Cards Portfolio [Member] | Consumer Credit Card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost - Revolving Loans	188,681
Total Loans	188,681
Credit Cards Portfolio [Member] | Commercial Credit Card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost - Revolving Loans	178,287
Total Loans	178,287
Leases and Other Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	33,626
Amortized Cost Basis by Origination Year 2019	11,673
Amortized Cost Basis by Origination Year 2018	7,659
Amortized Cost Basis by Origination Year 2017	3,398
Amortized Cost Basis by Origination Year 2016	1,323
Amortized Cost Basis by Origination Year Prior to 2016	1,357
Amortized Cost - Revolving Loans	131,859
Total Loans	190,895
Leases and Other Portfolio [Member] | Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2019	915
Amortized Cost Basis by Origination Year 2017	787
Amortized Cost Basis by Origination Year Prior to 2016	711
Total Loans	2,413
Leases and Other Portfolio [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost Basis by Origination Year 2020	33,626
Amortized Cost Basis by Origination Year 2019	10,758
Amortized Cost Basis by Origination Year 2018	7,659
Amortized Cost Basis by Origination Year 2017	2,611
Amortized Cost Basis by Origination Year 2016	1,323
Amortized Cost Basis by Origination Year Prior to 2016	646
Amortized Cost - Revolving Loans	131,859
Total Loans	$ 188,482