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, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 423,360	$ 1,620,118
2021	1,712,119	1,183,367
2020	1,285,302	798,755
2019	846,207	677,205
2018	737,496	638,690
Prior	2,650,718	2,001,549
Revolving loans amortized cost basis	873,855	904,441
Revolving loans converted to term loans	62,627	63,588
Total	8,591,684	7,887,713
Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	310,245	1,140,847
2021	1,276,308	984,337
2020	1,062,243	608,538
2019	663,980	557,498
2018	612,528	532,629
Prior	2,296,106	1,755,641
Revolving loans amortized cost basis	209,412	169,762
Revolving loans converted to term loans	40,019	40,478
Total	6,470,841	5,789,730
Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	3,150	10,511
2021	20,766	15,896
2020	24,308	7,236
2019	0	3,359
2018	5,171	0
Prior	0	0
Revolving loans amortized cost basis	20,083	25,262
Revolving loans converted to term loans	0	0
Total	73,478	62,264
SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	29,451	70,929
2021	65,744	36,468
2020	37,879	11,129
2019	13,222	36,853
2018	33,522	46,652
Prior	131,219	86,569
Revolving loans amortized cost basis	201	0
Revolving loans converted to term loans	0	0
Total	311,238	288,600
SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	183,614
2021	113,320	2,971
2020	7,869	0
2019	0	0
2018	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	121,189	186,585
Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	44,239	147,294
2021	165,583	83,879
2020	92,633	127,376
2019	122,880	57,798
2018	59,465	33,354
Prior	113,542	74,101
Revolving loans amortized cost basis	316,489	279,019
Revolving loans converted to term loans	9,949	10,242
Total	924,780	813,063
Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	749	2,808
2021	4,012	942
2020	3,138	1,285
2019	1,175	1,072
2018	2,934	95
Prior	2,232	295
Revolving loans amortized cost basis	270,813	371,291
Revolving loans converted to term loans	7,731	8,431
Total	292,784	386,219
Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	9,310
2021	13,087	7,666
2020	7,416	0
2019	4,417	279
2018	5,196	9,528
Prior	35,427	19,150
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	65,543	45,933
SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	29,913	48,821
2021	48,149	49,261
2020	48,027	41,776
2019	39,231	19,877
2018	18,257	16,046
Prior	70,705	64,017
Revolving loans amortized cost basis	451	451
Revolving loans converted to term loans	403	405
Total	255,136	240,654
Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	5,613	5,984
2021	5,150	1,947
2020	1,789	1,415
2019	1,302	469
2018	423	386
Prior	1,487	1,776
Revolving loans amortized cost basis	56,406	58,656
Revolving loans converted to term loans	4,525	4,032
Total	76,695	74,665
Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	422,849	1,613,286
2021	1,698,664	1,160,790
2020	1,253,006	780,690
2019	827,483	646,886
2018	695,279	581,735
Prior	2,530,706	1,939,076
Revolving loans amortized cost basis	851,254	872,585
Revolving loans converted to term loans	44,971	44,388
Total	8,324,212	7,639,436
Pass [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	309,734	1,137,714
2021	1,266,416	963,697
2020	1,034,822	591,202
2019	650,330	534,468
2018	584,265	484,721
Prior	2,195,297	1,704,267
Revolving loans amortized cost basis	203,627	156,841
Revolving loans converted to term loans	34,407	33,564
Total	6,278,898	5,606,474
Pass [Member] \| Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	3,150	10,511
2021	20,766	15,896
2020	24,308	7,236
2019	0	0
2018	1,389	0
Prior	0	0
Revolving loans amortized cost basis	20,083	25,262
Revolving loans converted to term loans	0	0
Total	69,696	58,905
Pass [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	29,451	70,929
2021	65,744	36,468
2020	36,025	11,129
2019	11,881	36,068
2018	31,312	38,504
Prior	116,138	78,527
Revolving loans amortized cost basis	201	0
Revolving loans converted to term loans	0	0
Total	290,752	271,625
Pass [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	183,614
2021	112,623	2,969
2020	7,867	0
2019	0	0
2018	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	120,490	186,583
Pass [Member] \| Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	44,239	145,494
2021	163,488	81,944
2020	90,575	126,647
2019	119,147	54,690
2018	53,297	32,455
Prior	112,214	73,600
Revolving loans amortized cost basis	307,641	267,659
Revolving loans converted to term loans	6,954	6,992
Total	897,555	789,481
Pass [Member] \| Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	749	1,756
2021	4,012	942
2020	3,138	1,285
2019	1,175	1,035
2018	1,140	95
Prior	1,334	295
Revolving loans amortized cost basis	263,440	364,312
Revolving loans converted to term loans	399	454
Total	275,387	370,174
Pass [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	9,310
2021	13,087	7,666
2020	7,416	0
2019	4,417	279
2018	5,196	9,528
Prior	34,896	18,811
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	65,012	45,594
Pass [Member] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	29,913	48,813
2021	48,149	49,261
2020	47,066	41,776
2019	39,231	19,877
2018	18,257	16,046
Prior	69,355	61,965
Revolving loans amortized cost basis	451	451
Revolving loans converted to term loans	0	0
Total	252,422	238,189
Pass [Member] \| Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	5,613	5,145
2021	4,379	1,947
2020	1,789	1,415
2019	1,302	469
2018	423	386
Prior	1,472	1,611
Revolving loans amortized cost basis	55,811	58,060
Revolving loans converted to term loans	3,211	3,378
Total	74,000	72,411
Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	511	6,588
2021	9,550	22,569
2020	31,735	14,604
2019	17,951	20,852
2018	28,291	47,712
Prior	92,518	47,260
Revolving loans amortized cost basis	15,160	23,909
Revolving loans converted to term loans	7,648	8,681
Total	203,364	192,175
Special Mention [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	511	3,133
2021	6,368	20,640
2020	26,868	14,477
2019	13,203	16,097
2018	21,280	43,262
Prior	86,656	44,045
Revolving loans amortized cost basis	3,285	6,970
Revolving loans converted to term loans	5,500	6,800
Total	163,671	155,424
Special Mention [Member] \| Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	3,359
2018	3,782	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	3,782	3,359
Special Mention [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	1,854	0
2019	1,341	0
2018	1,442	4,056
Prior	5,224	2,700
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	9,861	6,756
Special Mention [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0
2021	562	0
2020	0	0
2019	0	0
2018	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	562	0
Special Mention [Member] \| Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	1,556
2021	1,849	1,929
2020	2,052	127
2019	3,407	1,396
2018	1,787	394
Prior	299	26
Revolving loans amortized cost basis	7,338	9,369
Revolving loans converted to term loans	463	177
Total	17,195	14,974
Special Mention [Member] \| Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	1,052
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior	0	0
Revolving loans amortized cost basis	3,947	6,979
Revolving loans converted to term loans	1,283	1,301
Total	5,230	9,332
Special Mention [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior	339	339
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	339	339
Special Mention [Member] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	8
2021	0	0
2020	961	0
2019	0	0
2018	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	961	8
Special Mention [Member] \| Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	839
2021	771	0
2020		0
2019	0	0
2018	0	0
Prior	0	150
Revolving loans amortized cost basis	590	591
Revolving loans converted to term loans	402	403
Total	1,763	1,983
Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022		244
2021	3,905	8
2020	561	3,461
2019	773	9,467
2018	13,926	9,243
Prior	27,494	15,213
Revolving loans amortized cost basis	7,441	7,947
Revolving loans converted to term loans	10,008	10,519
Total	64,108	56,102
Substandard [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	3,524	0
2020	553	2,859
2019	447	6,933
2018	6,983	4,646
Prior	14,153	7,329
Revolving loans amortized cost basis	2,500	5,951
Revolving loans converted to term loans	112	114
Total	28,272	27,832
Substandard [Member] \| Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	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]
2022	0	0
2021	0	0
2020	0	0
2019	0	785
2018	768	4,092
Prior	9,857	5,342
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	10,625	10,219
Substandard [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	135	2
2020	2	0
2019	0	0
2018	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	137	2
Substandard [Member] \| Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	244
2021	246	6
2020	6	602
2019	326	1,712
2018	4,381	505
Prior	1,029	475
Revolving loans amortized cost basis	1,510	1,991
Revolving loans converted to term loans	2,532	3,073
Total	10,030	8,608
Substandard [Member] \| Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	37
2018	1,794	0
Prior	898	0
Revolving loans amortized cost basis	3,426	0
Revolving loans converted to term loans	6,049	6,676
Total	12,167	6,713
Substandard [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior	192	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	192	0
Substandard [Member] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior	1,350	2,052
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	403	405
Total	1,753	2,457
Substandard [Member] \| Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior	15	15
Revolving loans amortized cost basis	5	5
Revolving loans converted to term loans	912	251
Total	932	271
Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	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]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	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]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	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]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	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]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	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 And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	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