Loans and Allowance for Credit Losses - Summary of Amortized Cost Balance of Financial Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	$ 17,731,700	$ 17,170,871
Related Allowance for Credit Losses	181,333	196,711	$ 205,773	$ 218,583
Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	110,175	92,032
Related Allowance for Credit Losses	500	2,421
Amortized Cost of Collateral Dependent Assets with no related Allowance	100,808	85,680
Commercial and Industrial Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	7,613,899	7,258,120
Related Allowance for Credit Losses	118,668	123,732	119,568	122,700
Commercial and Industrial Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	91,053	82,845
Related Allowance for Credit Losses	500	2,421
Amortized Cost of Collateral Dependent Assets with no related Allowance	81,686	76,493
Commercial and Industrial Portfolio [Member] | Equipment/Accounts Receivable/Inventory [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	7,465,578	7,085,191
Commercial and Industrial Portfolio [Member] | Equipment/Accounts Receivable/Inventory [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	91,053	82,845
Related Allowance for Credit Losses	500	2,421
Amortized Cost of Collateral Dependent Assets with no related Allowance	81,686	76,493
Commercial and Industrial Portfolio [Member] | Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	142,030	154,342
Specialty Lending Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	505,860	522,362
Related Allowance for Credit Losses	861	1,738	4,673	5,219
Specialty Lending Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	11,797
Amortized Cost of Collateral Dependent Assets with no related Allowance	11,797
Specialty Lending Portfolio [Member] | Asset-based Lending [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	505,860	415,207
Specialty Lending Portfolio [Member] | Asset-based Lending [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	11,797
Amortized Cost of Collateral Dependent Assets with no related Allowance	11,797
Specialty Lending Portfolio [Member] | Factoring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets		107,155
Commercial Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	6,419,510	6,267,544
Related Allowance for Credit Losses	47,310	56,265	60,043	61,931
Commercial Real Estate Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	2,836	4,877
Amortized Cost of Collateral Dependent Assets with no related Allowance	2,836	4,877
Commercial Real Estate Portfolio [Member] | Owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	1,971,958	1,866,538
Commercial Real Estate Portfolio [Member] | Owner-occupied [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	2,293	2,764
Amortized Cost of Collateral Dependent Assets with no related Allowance	2,293	2,764
Commercial Real Estate Portfolio [Member] | Non-owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	2,866,445	2,906,179
Commercial Real Estate Portfolio [Member] | Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	475,261	480,268
Commercial Real Estate Portfolio [Member] | Farmland [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	440	487
Amortized Cost of Collateral Dependent Assets with no related Allowance	440	487
Commercial Real Estate Portfolio [Member] | 5+ Multi-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	193,809	205,312
Commercial Real Estate Portfolio [Member] | 1-4 Family Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	71,148	76,255
Commercial Real Estate Portfolio [Member] | General Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	840,889	732,992
Commercial Real Estate Portfolio [Member] | General Construction [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	103	1,626
Amortized Cost of Collateral Dependent Assets with no related Allowance	103	1,626
Consumer Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	2,393,314	2,320,033
Related Allowance for Credit Losses	4,037	3,921	4,183	6,586
Consumer Real Estate Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	3,892	4,210
Amortized Cost of Collateral Dependent Assets with no related Allowance	3,892	4,210
Consumer Real Estate Portfolio [Member] | HELOC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	312,743	331,638
Consumer Real Estate Portfolio [Member] | HELOC [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	2,449	2,488
Amortized Cost of Collateral Dependent Assets with no related Allowance	2,449	2,488
Consumer Real Estate Portfolio [Member] | First Lien: 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	2,058,519	1,966,335
Consumer Real Estate Portfolio [Member] | First Lien: 1-4 Family [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	1,370	1,647
Amortized Cost of Collateral Dependent Assets with no related Allowance	1,370	1,647
Consumer Real Estate Portfolio [Member] | Junior Lien: 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	22,052	22,060
Consumer Real Estate Portfolio [Member] | Junior Lien: 1-4 Family [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	73	75
Amortized Cost of Collateral Dependent Assets with no related Allowance	73	75
Consumer Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	132,815	129,135
Related Allowance for Credit Losses	418	845	603	1,480
Consumer Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	572	75
Amortized Cost of Collateral Dependent Assets with no related Allowance	572	75
Consumer Portfolio [Member] | Revolving Line [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	60,448	61,143
Consumer Portfolio [Member] | Revolving Line [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	496
Amortized Cost of Collateral Dependent Assets with no related Allowance	496
Consumer Portfolio [Member] | Auto [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	24,347	24,929
Consumer Portfolio [Member] | Auto [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	58	38
Amortized Cost of Collateral Dependent Assets with no related Allowance	58	38
Consumer Portfolio [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	48,020	43,063
Consumer Portfolio [Member] | Other [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	18	37
Amortized Cost of Collateral Dependent Assets with no related Allowance	18	37
Leases and Other Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	269,202	282,288
Related Allowance for Credit Losses	2,175	2,195	$ 1,600	$ 2,271
Leases and Other Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	25	25
Amortized Cost of Collateral Dependent Assets with no related Allowance	25	25
Leases and Other Portfolio [Member] | Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	2,137	2,167
Leases and Other Portfolio [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	267,065	280,121
Leases and Other Portfolio [Member] | Other [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost of Collateral Dependent Assets	25	25
Amortized Cost of Collateral Dependent Assets with no related Allowance	$ 25	$ 25