Loans and Allowance for Credit Losses - Summary of Amortized Cost Balance of Financial Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	$ 22,483,542		$ 21,031,189
Related Allowance for Credit Losses	224,989	$ 212,850	194,243	$ 166,605	$ 181,333	$ 196,711
Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	19,640		21,618
Related Allowance for Credit Losses	2,995		719
Amortized Cost of Collateral Dependent Assets with no related Allowance	16,645		18,524
Commercial and Industrial Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	9,901,347		9,205,986
Related Allowance for Credit Losses	163,810	154,484	136,737	112,942	118,668	123,732
Commercial and Industrial Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	11,918		13,972
Related Allowance for Credit Losses	1,138		713
Amortized Cost of Collateral Dependent Assets with no related Allowance	10,780		11,534
Commercial and Industrial Portfolio [Member] | Equipment/Accounts Receivable/Inventory [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	9,738,652		9,024,216
Commercial and Industrial Portfolio [Member] | Equipment/Accounts Receivable/Inventory [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	11,918		13,972
Related Allowance for Credit Losses	1,138		713
Amortized Cost of Collateral Dependent Assets with no related Allowance	10,780		11,534
Commercial and Industrial Portfolio [Member] | Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	157,667		173,841
Specialty Lending Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	561,216		602,706
Related Allowance for Credit Losses		922		1,133	861	1,738
Specialty Lending Portfolio [Member] | Asset-based Lending [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	561,216		602,706
Commercial Real Estate Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	8,268,217		7,616,086
Related Allowance for Credit Losses	42,192	40,514	39,370	37,240	47,310	56,265
Commercial Real Estate Portfolio Segment | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	2,538		2,679
Related Allowance for Credit Losses	1,857
Amortized Cost of Collateral Dependent Assets with no related Allowance	681		2,679
Commercial Real Estate Portfolio Segment | Owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	2,159,615		2,132,838
Commercial Real Estate Portfolio Segment | Owner-occupied [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	2,243		2,204
Related Allowance for Credit Losses	1,857
Amortized Cost of Collateral Dependent Assets with no related Allowance	386		2,204
Commercial Real Estate Portfolio Segment | Non-owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	3,308,055		3,244,598
Commercial Real Estate Portfolio Segment | Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	522,998		548,113
Commercial Real Estate Portfolio Segment | Farmland [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	198		374
Amortized Cost of Collateral Dependent Assets with no related Allowance	198		374
Commercial Real Estate Portfolio Segment | 5+ Multi-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	127,845		166,781
Commercial Real Estate Portfolio Segment | 1-4 Family Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	93,915		77,179
Commercial Real Estate Portfolio Segment | General Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	2,055,789		1,446,577
Commercial Real Estate Portfolio Segment | General Construction [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	97		101
Amortized Cost of Collateral Dependent Assets with no related Allowance	97		101
Consumer Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	2,918,426		2,723,269
Related Allowance for Credit Losses	6,527	5,616	6,148	4,565	4,037	3,921
Consumer Real Estate Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	5,146		4,882
Related Allowance for Credit Losses			6
Amortized Cost of Collateral Dependent Assets with no related Allowance	5,146		4,226
Consumer Real Estate Portfolio [Member] | HELOC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	349,542		347,169
Consumer Real Estate Portfolio [Member] | HELOC [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	1,911		2,562
Amortized Cost of Collateral Dependent Assets with no related Allowance	1,911		2,562
Consumer Real Estate Portfolio [Member] | First Lien: 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	2,532,769		2,343,998
Consumer Real Estate Portfolio [Member] | First Lien: 1-4 Family [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	3,154		2,253
Related Allowance for Credit Losses			6
Amortized Cost of Collateral Dependent Assets with no related Allowance	3,154		1,597
Consumer Real Estate Portfolio [Member] | Junior Lien: 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	36,115		32,102
Consumer Real Estate Portfolio [Member] | Junior Lien: 1-4 Family [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	81		67
Amortized Cost of Collateral Dependent Assets with no related Allowance	81		67
Consumer Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	131,292		145,666
Related Allowance for Credit Losses	417	453	494	863	418	845
Consumer Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	38		61
Amortized Cost of Collateral Dependent Assets with no related Allowance	38		61
Consumer Portfolio [Member] | Revolving Line [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	48,164		60,587
Consumer Portfolio [Member] | Auto [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	23,215		23,359
Consumer Portfolio [Member] | Auto [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	23		46
Amortized Cost of Collateral Dependent Assets with no related Allowance	23		46
Consumer Portfolio [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	59,913		61,720
Consumer Portfolio [Member] | Other [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	15		15
Amortized Cost of Collateral Dependent Assets with no related Allowance	15		15
Leases and Other Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	257,892		305,804
Related Allowance for Credit Losses	1,984	$ 2,049	2,221	$ 2,024	$ 2,175	$ 2,195
Leases and Other Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross			24
Amortized Cost of Collateral Dependent Assets with no related Allowance			24
Leases and Other Portfolio [Member] | Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	1,902		1,936
Leases and Other Portfolio [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross	$ 255,990		303,868
Leases and Other Portfolio [Member] | Other [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes Receivable Gross			24
Amortized Cost of Collateral Dependent Assets with no related Allowance			$ 24