Loans and Allowance for Credit Losses - Summary of Amortized Cost Balance of Financial Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 22,881,689		$ 21,031,189
Related Allowance for Credit Losses	224,348	$ 224,989	194,243	$ 187,432	$ 166,605	$ 196,711
Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	32,746		21,618
Related Allowance for Credit Losses	2,467		719
Amortized Cost of Collateral Dependent Assets with no related Allowance	30,280		18,524
Commercial and Industrial Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	9,789,685		9,205,986
Related Allowance for Credit Losses	158,218	163,810	136,737	133,105	112,942	123,732
Commercial and Industrial Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	9,282		13,972
Related Allowance for Credit Losses	610		713
Amortized Cost of Collateral Dependent Assets with no related Allowance	8,673		11,534
Commercial and Industrial Portfolio [Member] | Equipment/Accounts Receivable/Inventory [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	9,605,468		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]
Financing Receivable, before Allowance for Credit Loss	9,282		13,972
Related Allowance for Credit Losses	610		713
Amortized Cost of Collateral Dependent Assets with no related Allowance	8,673		11,534
Commercial and Industrial Portfolio [Member] | Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	167,096		173,841
Specialty Lending Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	522,419		602,706
Related Allowance for Credit Losses					1,133	1,738
Specialty Lending Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	15,230
Amortized Cost of Collateral Dependent Assets with no related Allowance	15,230
Specialty Lending Portfolio [Member] | Asset-based Lending [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	522,419		602,706
Specialty Lending Portfolio [Member] | Asset-based Lending [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	15,230
Amortized Cost of Collateral Dependent Assets with no related Allowance	15,230
Commercial Real Estate Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	8,778,638		7,616,086
Related Allowance for Credit Losses	45,716	42,192	39,370	38,149	37,240	56,265
Commercial Real Estate Portfolio Segment | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,491		2,679
Related Allowance for Credit Losses	1,857
Amortized Cost of Collateral Dependent Assets with no related Allowance	634		2,679
Commercial Real Estate Portfolio Segment | Owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,151,690		2,132,838
Commercial Real Estate Portfolio Segment | Owner-occupied [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,201		2,204
Related Allowance for Credit Losses	1,857
Amortized Cost of Collateral Dependent Assets with no related Allowance	344		2,204
Commercial Real Estate Portfolio Segment | Non-owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	3,364,007		3,244,598
Commercial Real Estate Portfolio Segment | Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	514,495		548,113
Commercial Real Estate Portfolio Segment | Farmland [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	195		374
Amortized Cost of Collateral Dependent Assets with no related Allowance	195		374
Commercial Real Estate Portfolio Segment | 5+ Multi-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	301,268		166,781
Commercial Real Estate Portfolio Segment | 1-4 Family Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	109,160		77,179
Commercial Real Estate Portfolio Segment | General Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,338,018		1,446,577
Commercial Real Estate Portfolio Segment | General Construction [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	95		101
Amortized Cost of Collateral Dependent Assets with no related Allowance	95		101
Consumer Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,924,515		2,723,269
Related Allowance for Credit Losses	6,826	6,527	6,148	4,998	4,565	3,921
Consumer Real Estate Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,706		4,882
Related Allowance for Credit Losses			6
Amortized Cost of Collateral Dependent Assets with no related Allowance	5,706		4,226
Consumer Real Estate Portfolio [Member] | HELOC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	349,578		347,169
Consumer Real Estate Portfolio [Member] | HELOC [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,296		2,562
Amortized Cost of Collateral Dependent Assets with no related Allowance	2,296		2,562
Consumer Real Estate Portfolio [Member] | First Lien: 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,538,870		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]
Financing Receivable, before Allowance for Credit Loss	3,315		2,253
Related Allowance for Credit Losses			6
Amortized Cost of Collateral Dependent Assets with no related Allowance	3,315		1,597
Consumer Real Estate Portfolio [Member] | Junior Lien: 1-4 Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	36,067		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]
Financing Receivable, before Allowance for Credit Loss	95		67
Amortized Cost of Collateral Dependent Assets with no related Allowance	95		67
Consumer Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	143,721		145,666
Related Allowance for Credit Losses	498	417	494	428	863	845
Consumer Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	37		61
Amortized Cost of Collateral Dependent Assets with no related Allowance	37		61
Consumer Portfolio [Member] | Revolving Line [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	53,888		60,587
Consumer Portfolio [Member] | Auto [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	24,886		23,359
Consumer Portfolio [Member] | Auto [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	20		46
Amortized Cost of Collateral Dependent Assets with no related Allowance	20		46
Consumer Portfolio [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	64,947		61,720
Consumer Portfolio [Member] | Other [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	17		15
Amortized Cost of Collateral Dependent Assets with no related Allowance	17		15
Leases and Other Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	272,147		305,804
Related Allowance for Credit Losses	2,488	$ 1,984	2,221	$ 1,658	$ 2,024	$ 2,195
Leases and Other Portfolio [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss			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]
Financing Receivable, before Allowance for Credit Loss	1,733		1,936
Leases and Other Portfolio [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 270,414		303,868
Leases and Other Portfolio [Member] | Other [Member] | Collateral Dependent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss			24
Amortized Cost of Collateral Dependent Assets with no related Allowance			$ 24