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	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
2021	$ 1,620,118	$ 2,129,465
2020	1,183,367	954,344
2019	798,755	804,015
2018	677,205	840,334
2017	638,690	666,584
Prior	2,001,549	1,975,259
Revolving loans amortized cost basis	904,441	924,822
Revolving loans converted to term loans	63,588	53,985
Total	7,887,713	8,348,808
Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	1,140,847	988,831
2020	984,337	698,744
2019	608,538	639,959
2018	557,498	668,892
2017	532,629	570,031
Prior	1,755,641	1,710,506
Revolving loans amortized cost basis	169,762	198,663
Revolving loans converted to term loans	40,478	25,883
Total	5,789,730	5,501,509
Construction Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	10,511	14,511
2020	15,896	9,350
2019	7,236	14,945
2018	3,359	2,258
2017	0	0
Prior	0	4
Revolving loans amortized cost basis	25,262	44,077
Revolving loans converted to term loans	0	0
Total	62,264	85,145
SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	70,929	47,901
2020	36,468	12,821
2019	11,129	45,854
2018	36,853	69,788
2017	46,652	29,026
Prior	86,569	95,530
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	2,976
Total	288,600	303,896
SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	183,614	882,986
2020	2,971	0
2019	0	0
2018	0	0
2017	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	186,585	882,986
Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	147,294	110,819
2020	83,879	169,991
2019	127,376	68,341
2018	57,798	59,353
2017	33,354	32,529
Prior	74,101	80,995
Revolving loans amortized cost basis	279,019	281,322
Revolving loans converted to term loans	10,242	8,712
Total	813,063	812,062
Dairy & Livestock and Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	2,808	1,919
2020	942	1,765
2019	1,285	2,347
2018	1,072	6,373
2017	95	2,405
Prior	295	320
Revolving loans amortized cost basis	371,291	332,466
Revolving loans converted to term loans	8,431	13,551
Total	386,219	361,146
Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	9,310	8,478
2020	7,666
2019	0	2,556
2018	279	10,249
2017	9,528	3,586
Prior	19,150	20,678
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	45,933	45,547
SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	48,821	65,463
2020	49,261	59,596
2019	41,776	29,142
2018	19,877	22,452
2017	16,046	27,421
Prior	64,017	66,002
Revolving loans amortized cost basis	451	3
Revolving loans converted to term loans	405	432
Total	240,654	270,511
Consumer and other loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	5,984	8,557
2020	1,947	2,077
2019	1,415	871
2018	469	969
2017	386	1,586
Prior	1,776	1,224
Revolving loans amortized cost basis	58,656	68,291
Revolving loans converted to term loans	4,032	2,431
Total	74,665	86,006
Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	1,613,286	2,112,914
2020	1,160,790	944,750
2019	780,690	763,869
2018	646,886	774,130
2017	581,735	640,874
Prior	1,939,076	1,893,124
Revolving loans amortized cost basis	872,585	880,898
Revolving loans converted to term loans	44,388	35,633
Total	7,639,436	8,046,192
Pass [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	1,137,714	979,499
2020	963,697	691,091
2019	591,202	607,753
2018	534,468	617,640
2017	484,721	550,105
Prior	1,704,267	1,646,876
Revolving loans amortized cost basis	156,841	192,583
Revolving loans converted to term loans	33,564	24,548
Total	5,606,474	5,310,095
Pass [Member] \| Construction Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	10,511	14,511
2020	15,896	9,350
2019	7,236	14,945
2018	0	2,258
2017	0	0
Prior	0	4
Revolving loans amortized cost basis	25,262	44,077
Revolving loans converted to term loans	0	0
Total	58,905	85,145
Pass [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	70,929	47,901
2020	36,468	12,821
2019	11,129	44,950
2018	36,068	58,839
2017	38,504	26,136
Prior	78,527	86,085
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	2,976
Total	271,625	279,708
Pass [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	183,614	882,986
2020	2,969	0
2019	0	0
2018	0	0
2017	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	186,583	882,986
Pass [Member] \| Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	145,494	104,478
2020	81,944	168,050
2019	126,647	62,453
2018	54,690	56,043
2017	32,455	32,149
Prior	73,600	76,019
Revolving loans amortized cost basis	267,659	257,250
Revolving loans converted to term loans	6,992	6,058
Total	789,481	762,500
Pass [Member] \| Dairy & Livestock and Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	1,756	1,041
2020	942	1,765
2019	1,285	1,199
2018	1,035	5,680
2017	95	120
Prior	295	320
Revolving loans amortized cost basis	364,312	319,211
Revolving loans converted to term loans	454	363
Total	370,174	329,699
Pass [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	9,310	8,478
2020	7,666	0
2019	0	2,556
2018	279	10,249
2017	9,528	3,586
Prior	18,811	20,266
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	45,594	45,135
Pass [Member] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	48,813	65,463
2020	49,261	59,596
2019	41,776	29,142
2018	19,877	22,452
2017	16,046	27,192
Prior	61,965	62,593
Revolving loans amortized cost basis	451	3
Revolving loans converted to term loans	0	0
Total	238,189	266,441
Pass [Member] \| Consumer and other loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	5,145	8,557
2020	1,947	2,077
2019	1,415	871
2018	469	969
2017	386	1,586
Prior	1,611	961
Revolving loans amortized cost basis	58,060	67,774
Revolving loans converted to term loans	3,378	1,688
Total	72,411	84,483
Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	6,588	12,205
2020	22,569	8,243
2019	14,604	32,305
2018	20,852	50,344
2017	47,712	18,829
Prior	47,260	61,325
Revolving loans amortized cost basis	23,909	36,887
Revolving loans converted to term loans	8,681	3,659
Total	192,175	223,797
Special Mention [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	3,133	9,332
2020	20,640	7,162
2019	14,477	30,049
2018	16,097	43,870
2017	43,262	17,398
Prior	44,045	49,840
Revolving loans amortized cost basis	6,970	5,720
Revolving loans converted to term loans	6,800	994
Total	155,424	164,365
Special Mention [Member] \| Construction Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	3,359	0
2017	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	3,359	0
Special Mention [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	5,446
2017	4,056	1,336
Prior	2,700	5,648
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	6,756	12,430
Special Mention [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	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]
2021	1,556	1,995
2020	1,929	1,081
2019	127	1,892
2018	1,396	1,028
2017	394	95
Prior	26	4,882
Revolving loans amortized cost basis	9,369	17,395
Revolving loans converted to term loans	177	1,132
Total	14,974	29,500
Special Mention [Member] \| Dairy & Livestock and Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	1,052	878
2020	0	0
2019	0	364
2018	0	0
2017	0	0
Prior	0	0
Revolving loans amortized cost basis	6,979	13,255
Revolving loans converted to term loans	1,301	1,511
Total	9,332	16,008
Special Mention [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	0	0
Prior	339	412
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	339	412
Special Mention [Member] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	8	0
2020	0	0
2019	0	0
2018	0	0
2017	0	0
Prior	0	452
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	8	452
Special Mention [Member] \| Consumer and other loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	839	0
2020	0	0
2019	0	0
2018	0	0
2017	0	0
Prior	150	91
Revolving loans amortized cost basis	591	517
Revolving loans converted to term loans	403	22
Total	1,983	630
Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	244	4,346
2020	8	1,351
2019	3,461	7,841
2018	9,467	15,860
2017	9,243	6,881
Prior	15,213	20,810
Revolving loans amortized cost basis	7,947	7,037
Revolving loans converted to term loans	10,519	14,693
Total	56,102	78,819
Substandard [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	491
2019	2,859	2,157
2018	6,933	7,382
2017	4,646	2,528
Prior	7,329	13,790
Revolving loans amortized cost basis	5,951	360
Revolving loans converted to term loans	114	341
Total	27,832	27,049
Substandard [Member] \| Construction Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	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]
2021	0	0
2020	0	0
2019	0	904
2018	785	5,503
2017	4,092	1,554
Prior	5,342	3,797
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	10,219	11,758
Substandard [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	2	0
2019	0	0
2018	0	0
2017	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	2	0
Substandard [Member] \| Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	244	4,346
2020	6	860
2019	602	3,996
2018	1,712	2,282
2017	505	285
Prior	475	94
Revolving loans amortized cost basis	1,991	6,677
Revolving loans converted to term loans	3,073	1,522
Total	8,608	20,062
Substandard [Member] \| Dairy & Livestock and Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020		0
2019	0	784
2018	37	693
2017	0	2,285
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	6,676	11,677
Total	6,713	15,439
Substandard [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	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] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	0	229
Prior	2,052	2,957
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	405	432
Total	2,457	3,618
Substandard [Member] \| Consumer and other loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	0	0
Prior	15	172
Revolving loans amortized cost basis	5	0
Revolving loans converted to term loans	251	721
Total	271	893
Doubtful & Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Doubtful & Loss [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Doubtful & Loss [Member] \| Construction Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Doubtful & Loss [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Doubtful & Loss [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	0
Doubtful & Loss [Member] \| Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0	0
2020	0	0
2019	0	0
2018	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