Loans and Lease Finance Receivables and Allowance for Credit Losses - Summary of loans by type and origination year, according to our internal risk ratings (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
2024	$ 486,523
2023	570,662	$ 651,552
2022	1,495,356	1,608,241
2021	1,284,963	1,402,964
2020	1,004,855	1,124,447
2019		668,632
Prior	2,645,131	2,453,629
Revolving loans amortized cost basis	990,088	943,285
Revolving loans converted to term loans	58,854	52,160
Total	8,536,432	8,904,910
Total Loans and Financing Receivables	8,536,432	8,904,910
Financing Receivable Accrued Interest Year Three Originated Two Years Before Current Fiscal Year Writeoff	300
Financing Receivable Accrued Interest Originated More than Five Years before Current Fiscal Year Writeoff	3,609	292
Gross Charge Offs Revolving Loans Amortized Term Loans	1
Gross charge-offs Revolving loans converted to term loans	498	113
Gross charge-off total	4,408	405
Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	480,552
2023	560,266	638,501
2022	1,448,946	1,593,595
2021	1,250,781	1,381,084
2020	966,628	1,065,424
2019		605,169
Prior	2,495,112	2,337,278
Revolving loans amortized cost basis	886,023	854,820
Revolving loans converted to term loans	45,785	44,899
Total	8,134,093	8,520,770
Total Loans and Financing Receivables	8,134,093	8,520,770
Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	4,795
2023	7,123	12,307
2022	37,531	6,262
2021	25,114	18,989
2020	23,089	25,622
2019		49,639
Prior	110,715	80,928
Revolving loans amortized cost basis	96,372	82,676
Revolving loans converted to term loans	8,051	5,520
Total	312,790	281,943
Total Loans and Financing Receivables	312,790	281,943
Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	1,176
2023	3,273	744
2022	8,879	8,384
2021	9,068	2,891
2020	15,138	33,401
2019		13,824
Prior	39,304	35,423
Revolving loans amortized cost basis	7,693	5,789
Revolving loans converted to term loans	5,018	1,741
Total	89,549	102,197
Total Loans and Financing Receivables	89,549	102,197
Doubtful & Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0
2022	0
2021	0	0
2020	0	0
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Total Loans and Financing Receivables	0	0
Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	310,235
2023	424,701	451,976
2022	1,259,406	1,327,587
2021	1,097,229	1,152,090
2020	860,687	938,359
2019		554,351
Prior	2,308,579	2,146,639
Revolving loans amortized cost basis	207,624	174,935
Revolving loans converted to term loans	38,991	38,568
Total	6,507,452	6,784,505
Total Loans and Financing Receivables	6,507,452	6,784,505
Financing Receivable Accrued Interest Originated More than Five Years before Current Fiscal Year Writeoff	2,258
Gross charge-off total	2,258
Commercial real estate loans [Member] \| Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	307,984
2023	419,547	447,991
2022	1,216,126	1,315,563
2021	1,066,694	1,133,331
2020	828,493	885,590
2019		497,541
Prior	2,170,119	2,041,329
Revolving loans amortized cost basis	197,991	171,223
Revolving loans converted to term loans	37,704	38,568
Total	6,244,658	6,531,136
Total Loans and Financing Receivables	6,244,658	6,531,136
Commercial real estate loans [Member] \| Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	1,075
2023	4,910	3,241
2022	36,505	3,897
2021	21,478	15,868
2020	17,056	19,368
2019		43,824
Prior	104,201	74,673
Revolving loans amortized cost basis	3,937	2,911
Revolving loans converted to term loans	1,287	0
Total	190,449	163,782
Total Loans and Financing Receivables	190,449	163,782
Commercial real estate loans [Member] \| Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	1,176
2023	244	744
2022	6,775	8,127
2021	9,057	2,891
2020	15,138	33,401
2019		12,986
Prior	34,259	30,637
Revolving loans amortized cost basis	5,696	801
Revolving loans converted to term loans	0	0
Total	72,345	89,587
Total Loans and Financing Receivables	72,345	89,587
Commercial real estate loans [Member] \| Doubtful & Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Total Loans and Financing Receivables	0	0
Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	101,284
2023	105,484
2022	113,531
2021	69,886
2020	69,505
Prior	122,244
Revolving loans amortized cost basis	328,280
Revolving loans converted to term loans	14,964
Total	925,178
Total Loans and Financing Receivables	925,178
Financing Receivable Accrued Interest Year Three Originated Two Years Before Current Fiscal Year Writeoff	300
Financing Receivable Accrued Interest Originated More than Five Years before Current Fiscal Year Writeoff	1,186
Gross charge-offs Revolving loans converted to term loans	495	109
Gross charge-off total	1,981	109
Commercial And Industrial [Member] \| Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	100,465
2023	100,242
2022	111,982
2021	67,706
2020	69,084
Prior	118,069
Revolving loans amortized cost basis	318,147
Revolving loans converted to term loans	6,213
Total	891,908
Total Loans and Financing Receivables	891,908
Commercial And Industrial [Member] \| Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	819
2023	2,213
2022	1,026
2021	2,169
2020	421
Prior	4,175
Revolving loans amortized cost basis	8,136
Revolving loans converted to term loans	4,830
Total	23,789
Total Loans and Financing Receivables	23,789
Commercial And Industrial [Member] \| Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	3,029
2022	523
2021	11
2020	0
Prior	0
Revolving loans amortized cost basis	1,997
Revolving loans converted to term loans	3,921
Total	9,481
Total Loans and Financing Receivables	9,481
Commercial And Industrial [Member] \| Doubtful & Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0
2022	0
2021	0
2020	0
Prior	0
Revolving loans amortized cost basis	0
Revolving loans converted to term loans	0
Total	0
Total Loans and Financing Receivables	0
Construction Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	7,717
2023	315	1,274
2022	8,050	15,046
2021	0	24,418
2020	0	8,058
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	17,938
Revolving loans converted to term loans	0	0
Total	16,082	66,734
Total Loans and Financing Receivables	16,082	66,734
Construction Loans [Member] \| Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	7,717
2023	315	1,274
2022	8,050	15,046
2021	0	22,288
2020	0	8,058
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	17,938
Revolving loans converted to term loans	0	0
Total	16,082	64,604
Total Loans and Financing Receivables	16,082	64,604
Construction Loans [Member] \| Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	0
2021	0	2,130
2020	0	0
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	2,130
Total Loans and Financing Receivables	0	2,130
Construction Loans [Member] \| Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Total Loans and Financing Receivables	0	0
Construction Loans [Member] \| Doubtful & Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Total Loans and Financing Receivables	0	0
SBA Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	33,531
2023	16,064	20,701
2022	47,974	49,839
2021	49,147	51,038
2020	28,449	34,090
2019		8,117
Prior	97,848	106,834
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	273,013	270,619
Total Loans and Financing Receivables	273,013	270,619
Financing Receivable Accrued Interest Originated More than Five Years before Current Fiscal Year Writeoff	165	288
Gross charge-off total	165	288
SBA Loans [Member] \| Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	33,531
2023	16,064	20,701
2022	46,393	48,212
2021	47,810	51,038
2020	23,733	29,306
2019		6,236
Prior	92,012	101,856
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	259,543	257,349
Total Loans and Financing Receivables	259,543	257,349
SBA Loans [Member] \| Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	1,627
2021	1,337	0
2020	4,716	4,784
2019		1,132
Prior	1,830	1,760
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	7,883	9,303
Total Loans and Financing Receivables	7,883	9,303
SBA Loans [Member] \| Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	1,581	0
2021	0	0
2020	0	0
2019		749
Prior	4,006	3,218
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	5,587	3,967
Total Loans and Financing Receivables	5,587	3,967
SBA Loans [Member] \| Doubtful & Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Total Loans and Financing Receivables	0	0
SBA - PPP [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	0
2021	254	699
2020	520	2,037
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	774	2,736
Total Loans and Financing Receivables	774	2,736
SBA - PPP [Member] \| Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	0
2021	254	699
2020	520	2,037
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	774	2,736
Total Loans and Financing Receivables	774	2,736
SBA - PPP [Member] \| Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Total Loans and Financing Receivables	0	0
SBA - PPP [Member] \| Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Total Loans and Financing Receivables	0	0
SBA - PPP [Member] \| Doubtful & Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019		0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Total Loans and Financing Receivables	0	0
Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023		148,909
2022		144,842
2021		100,804
2020		89,295
2019		72,555
Prior		99,309
Revolving loans amortized cost basis		302,555
Revolving loans converted to term loans		11,626
Total	925,178	969,895
Total Loans and Financing Receivables	925,178	969,895
Commercial and Industrial [Member] \| Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023		141,080
2022		143,847
2021		100,059
2020		88,743
2019		68,352
Prior		94,027
Revolving loans amortized cost basis		289,539
Revolving loans converted to term loans		5,460
Total		931,107
Total Loans and Financing Receivables		931,107
Commercial and Industrial [Member] \| Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023		7,829
2022		738
2021		745
2020		552
2019		4,114
Prior		3,986
Revolving loans amortized cost basis		10,529
Revolving loans converted to term loans		5,347
Total		33,840
Total Loans and Financing Receivables		33,840
Commercial and Industrial [Member] \| Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023		0
2022		257
2021		0
2020		0
2019		89
Prior		1,296
Revolving loans amortized cost basis		2,487
Revolving loans converted to term loans		819
Total		4,948
Total Loans and Financing Receivables		4,948
Commercial and Industrial [Member] \| Doubtful & Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023		0
2022		0
2021		0
2020		0
2019		0
Prior		0
Revolving loans amortized cost basis		0
Revolving loans converted to term loans		0
Total		0
Total Loans and Financing Receivables		0
Dairy & Livestock and Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	3,713
2023	0	744
2022	0	0
2021	596	1,586
2020	786	931
2019		105
Prior	201	268
Revolving loans amortized cost basis	412,145	409,257
Revolving loans converted to term loans	2,463	0
Total	419,904	412,891
Total Loans and Financing Receivables	419,904	412,891
Dairy & Livestock and Agribusiness [Member] \| Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	812
2023	0	296
2022	0	0
2021	596	1,586
2020	786	931
2019		80
Prior	141	208
Revolving loans amortized cost basis	327,850	337,525
Revolving loans converted to term loans	13	0
Total	330,198	340,626
Total Loans and Financing Receivables	330,198	340,626
Dairy & Livestock and Agribusiness [Member] \| Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	2,901
2023	0	448
2022	0	0
2021	0	0
2020	0	0
2019		25
Prior	0	0
Revolving loans amortized cost basis	84,295	69,232
Revolving loans converted to term loans	1,650	0
Total	88,846	69,705
Total Loans and Financing Receivables	88,846	69,705
Dairy & Livestock and Agribusiness [Member] \| Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0

Loans and Lease Finance Receivables and Allowance for Credit Losses - Summary of loans by type and origination year, according to our internal risk ratings (Detail) - USD ($)
$ in Thousands