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	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
2023	$ 235,389	$ 1,683,162
2022	1,663,062	1,512,519
2021	1,493,610	1,178,645
2020	1,163,778	744,349
2019	717,255	633,929
Prior	2,782,565	2,265,644
Revolving loans amortized cost basis	829,498	1,002,474
Revolving loans converted to term loans	57,332	58,670
Total	8,942,489	9,079,392
Gross charge-off prior	110
Gross charge-offs total	110
Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	186,781	1,367,018
2022	1,359,549	1,209,404
2021	1,200,224	984,873
2020	982,436	592,100
2019	581,818	528,353
Prior	2,420,311	1,987,303
Revolving loans amortized cost basis	181,581	176,281
Revolving loans converted to term loans	37,602	39,616
Total	6,950,302	6,884,948
Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	3,704	17,203
2022	13,503	26,689
2021	34,209	16,578
2020	7,651	0
2019	0	4,951
Prior	5,044	0
Revolving loans amortized cost basis	19,881	22,850
Revolving loans converted to term loans	0	0
Total	83,992	88,271
SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	805	60,623
2022	58,361	54,781
2021	54,368	35,243
2020	34,951	8,781
2019	8,589	30,735
Prior	126,340	99,719
Revolving loans amortized cost basis	50	1,026
Revolving loans converted to term loans	0	0
Total	283,464	290,908
Gross charge-off prior	94
Gross charge-offs total	94
SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	5,515
2021	2,638	3,572
2020	3,186	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	5,824	9,087
Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	37,606	159,214
2022	156,545	135,923
2021	123,142	81,950
2020	80,438	103,844
2019	91,071	48,817
Prior	118,828	85,910
Revolving loans amortized cost basis	280,005	323,945
Revolving loans converted to term loans	10,532	9,080
Total	898,167	948,683
Gross charge-off prior	16
Gross charge-offs total	16
Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	1,005	1,248
2022	100	2,318
2021	1,842	1,555
2020	1,478	786
2019	307	210
Prior	2,453	741
Revolving loans amortized cost basis	294,360	419,199
Revolving loans converted to term loans	6,275	7,507
Total	307,820	433,564
Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023		6,442
2022	6,427	26,858
2021	26,857	6,814
2020	6,559	4,327
2019	4,322	4,948
Prior	35,387	31,737
Revolving loans amortized cost basis		0
Revolving loans converted to term loans		0
Total	79,552	81,126
SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	3,782	63,761
2022	62,559	46,748
2021	46,407	46,762
2020	45,966	33,585
2019	30,298	15,836
Prior	72,927	58,944
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	385	388
Total	262,324	266,024
Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	1,706
2022	6,018	4,283
2021	3,923	1,298
2020	1,113	926
2019	850	79
Prior	1,275	1,290
Revolving loans amortized cost basis	53,621	59,173
Revolving loans converted to term loans	2,538	2,079
Total	71,044	76,781
Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	228,715	1,674,387
2022	1,658,608	1,499,083
2021	1,484,744	1,149,567
2020	1,129,574	690,504
2019	660,877	599,162
Prior	2,647,212	2,163,284
Revolving loans amortized cost basis	793,882	963,645
Revolving loans converted to term loans	44,778	48,948
Total	8,648,390	8,788,580
Pass [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	185,194	1,363,733
2022	1,356,290	1,197,290
2021	1,192,562	957,965
2020	950,317	542,827
2019	532,910	506,613
Prior	2,302,301	1,889,478
Revolving loans amortized cost basis	180,989	175,373
Revolving loans converted to term loans	37,602	39,616
Total	6,738,165	6,672,895
Pass [Member] \| Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	3,704	17,203
2022	13,503	26,689
2021	34,209	16,578
2020	7,651	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	19,881	22,850
Revolving loans converted to term loans	0	0
Total	78,948	83,320
Pass [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	805	60,623
2022	58,361	54,781
2021	54,368	35,243
2020	34,951	7,460
2019	7,277	28,886
Prior	120,940	96,473
Revolving loans amortized cost basis	50	1,026
Revolving loans converted to term loans	0	0
Total	276,752	284,492
Pass [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	5,515
2021	2,638	3,572
2020	3,186	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	5,824	9,087
Pass [Member] \| Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	32,519	154,765
2022	155,350	135,162
2021	122,428	80,763
2020	79,288	101,192
2019	85,046	42,731
Prior	114,270	85,406
Revolving loans amortized cost basis	264,205	305,589
Revolving loans converted to term loans	5,865	7,775
Total	858,971	913,383
Pass [Member] \| Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	1,005	207
2022	100	2,318
2021	1,842	1,515
2020	1,478	187
2019	174	69
Prior	739	628
Revolving loans amortized cost basis	275,431	400,229
Revolving loans converted to term loans	342	450
Total	281,111	405,603
Pass [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023		6,442
2022	6,427	26,858
2021	26,857	6,814
2020	6,559	4,327
2019	4,322	4,948
Prior	34,984	31,292
Revolving loans amortized cost basis		0
Revolving loans converted to term loans		0
Total	79,149	80,681
Pass [Member] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	3,782	63,761
2022	62,559	46,748
2021	46,407	45,819
2020	45,031	33,585
2019	30,298	15,836
Prior	72,716	58,730
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	260,793	264,479
Pass [Member] \| Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	1,706	7,653
2022	6,018	3,722
2021	3,433	1,298
2020	1,113	926
2019	850	79
Prior	1,262	1,277
Revolving loans amortized cost basis	53,326	58,578
Revolving loans converted to term loans	969	1,107
Total	68,677	74,640
Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	6,674	7,240
2022	3,968	13,436
2021	8,866	12,686
2020	18,330	36,589
2019	42,539	28,398
Prior	109,869	78,625
Revolving loans amortized cost basis	32,181	33,783
Revolving loans converted to term loans	4,695	1,397
Total	227,122	212,154
Special Mention [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	1,587	3,285
2022	3,259	12,114
2021	7,662	11,284
2020	16,927	32,976
2019	35,911	21,646
Prior	100,504	76,290
Revolving loans amortized cost basis	592	908
Revolving loans converted to term loans	0	0
Total	166,442	158,503
Special Mention [Member] \| Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	4,951
Prior	5,044	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	5,044	4,951
Special Mention [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	1,321
2019	1,312	1,293
Prior	3,630	2,065
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	4,942	4,679
Special Mention [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Special Mention [Member] \| Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	5,087	3,955
2022	709	761
2021	714	459
2020	468	1,693
2019	5,183	462
Prior	438	8
Revolving loans amortized cost basis	12,370	15,156
Revolving loans converted to term loans	3,855	544
Total	28,824	23,038
Special Mention [Member] \| Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	599
2019	133	46
Prior	30	0
Revolving loans amortized cost basis	18,929	17,129
Revolving loans converted to term loans	751	853
Total	19,843	18,627
Special Mention [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023		0
2022		0
2021		0
2020		0
2019		0
Prior	223	262
Revolving loans amortized cost basis		0
Revolving loans converted to term loans		0
Total	223	262
Special Mention [Member] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	943
2020	935	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	935	943
Special Mention [Member] \| Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	0	561
2021	490	0
2020	0	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	290	590
Revolving loans converted to term loans	89	0
Total	869	1,151
Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	1,535
2022	486	0
2021	0	16,392
2020	15,874	17,256
2019	13,839	6,369
Prior	25,484	23,735
Revolving loans amortized cost basis	3,435	5,046
Revolving loans converted to term loans	7,859	8,325
Total	66,977	78,658
Substandard [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	15,624
2020	15,192	16,297
2019	12,997	94
Prior	17,506	21,535
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	45,695	53,550
Substandard [Member] \| Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Substandard [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	556
Prior	1,770	1,181
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	1,770	1,737
Substandard [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Substandard [Member] \| Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023		494
2022	486	0
2021		728
2020	682	959
2019	842	5,624
Prior	4,120	496
Revolving loans amortized cost basis	3,430	3,200
Revolving loans converted to term loans	812	761
Total	10,372	12,262
Substandard [Member] \| Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	1,041
2022	0	0
2021	0	40
2020	0	0
2019	0	95
Prior	1,684	113
Revolving loans amortized cost basis	0	1,841
Revolving loans converted to term loans	5,182	6,204
Total	6,866	9,334
Substandard [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023		0
2022		0
2021		0
2020		0
2019		0
Prior	180	183
Revolving loans amortized cost basis		0
Revolving loans converted to term loans		0
Total	180	183
Substandard [Member] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	211	214
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	385	388
Total	596	602
Substandard [Member] \| Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	13	13
Revolving loans amortized cost basis	5	5
Revolving loans converted to term loans	1,480	972
Total	1,498	990
Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Doubtful [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Doubtful [Member] \| Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Doubtful [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Doubtful [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	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