Loans and Allowance for Credit Losses - Summary of Amortized Cost Balance of Financial Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	$ 23,637,649	$ 23,172,484
Related Allowance for Credit Losses	229,979	222,996	$ 212,850	$ 194,243
Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	17,650	13,090
Amortized Cost of Collateral Dependent Assets with no related Allowance	17,650	13,090
Commercial and Industrial Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	9,940,487	9,929,929
Related Allowance for Credit Losses	139,824	155,658	154,484	136,737
Commercial and Industrial Portfolio [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	5,634	7,033
Amortized Cost of Collateral Dependent Assets with no related Allowance	5,634	7,033
Commercial and Industrial Portfolio [Member] | Equipment/Accounts Receivable/Inventory [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	9,753,354	9,732,083
Commercial and Industrial Portfolio [Member] | Equipment/Accounts Receivable/Inventory [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	5,634	7,033
Amortized Cost of Collateral Dependent Assets with no related Allowance	5,634	7,033
Commercial and Industrial Portfolio [Member] | Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	175,520	194,368
Specialty Lending Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	508,162	498,786
Related Allowance for Credit Losses			922
Specialty Lending Portfolio [Member] | Asset-based Lending [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	508,162	498,786
Commercial Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	9,285,165	8,893,926
Related Allowance for Credit Losses	66,291	45,507	40,514	39,370
Commercial Real Estate Portfolio [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	5,993	900
Amortized Cost of Collateral Dependent Assets with no related Allowance	5,993	900
Commercial Real Estate Portfolio [Member] | Owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	2,095,127	2,138,705
Commercial Real Estate Portfolio [Member] | Owner-occupied [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	604	632
Amortized Cost of Collateral Dependent Assets with no related Allowance	604	632
Commercial Real Estate Portfolio [Member] | Non-owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	3,546,898	3,272,549
Commercial Real Estate Portfolio [Member] | Non-owner-occupied [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	5,112
Amortized Cost of Collateral Dependent Assets with no related Allowance	5,112
Commercial Real Estate Portfolio [Member] | Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	507,429	505,982
Commercial Real Estate Portfolio [Member] | Farmland [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	152	175
Amortized Cost of Collateral Dependent Assets with no related Allowance	152	175
Commercial Real Estate Portfolio [Member] | 5+ Multi-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	448,704	364,063
Commercial Real Estate Portfolio [Member] | 1-4 Family Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	101,810	107,367
Commercial Real Estate Portfolio [Member] | General Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	2,585,197	2,505,260
Commercial Real Estate Portfolio [Member] | General Construction [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	125	93
Amortized Cost of Collateral Dependent Assets with no related Allowance	125	93
Consumer Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	2,972,731	2,960,632
Related Allowance for Credit Losses	3,399	6,941	5,616	6,148
Consumer Real Estate Portfolio [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	5,994	5,058
Amortized Cost of Collateral Dependent Assets with no related Allowance	5,994	5,058
Consumer Real Estate Portfolio [Member] | HELOC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	363,465	362,806
Consumer Real Estate Portfolio [Member] | HELOC [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	1,473	1,437
Amortized Cost of Collateral Dependent Assets with no related Allowance	1,473	1,437
Consumer Real Estate Portfolio [Member] | First Lien: 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	2,565,821	2,559,007
Consumer Real Estate Portfolio [Member] | First Lien: 1-4 Family [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	4,424	3,519
Amortized Cost of Collateral Dependent Assets with no related Allowance	4,424	3,519
Consumer Real Estate Portfolio [Member] | Junior Lien: 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	43,445	38,819
Consumer Real Estate Portfolio [Member] | Junior Lien: 1-4 Family [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	97	102
Amortized Cost of Collateral Dependent Assets with no related Allowance	97	102
Consumer Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	146,602	163,291
Related Allowance for Credit Losses	531	1,089	453	494
Consumer Portfolio [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	29	28
Amortized Cost of Collateral Dependent Assets with no related Allowance	29	28
Consumer Portfolio [Member] | Revolving Line [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	61,480	56,320
Consumer Portfolio [Member] | Auto [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	23,740	24,860
Consumer Portfolio [Member] | Auto [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	15	14
Amortized Cost of Collateral Dependent Assets with no related Allowance	15	14
Consumer Portfolio [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	61,382	82,111
Consumer Portfolio [Member] | Other [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	14	14
Amortized Cost of Collateral Dependent Assets with no related Allowance	14	14
Leases and Other Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	246,004	301,964
Related Allowance for Credit Losses	1,557	2,608	$ 2,049	$ 2,221
Leases and Other Portfolio [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross		71
Amortized Cost of Collateral Dependent Assets with no related Allowance		71
Leases and Other Portfolio [Member] | Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	1,699	1,716
Leases and Other Portfolio [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	$ 244,305	300,248
Leases and Other Portfolio [Member] | Other [Member] | Collateral Pledged [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross		71
Amortized Cost of Collateral Dependent Assets with no related Allowance		$ 71