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	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 1,294,170	$ 1,620,118
2021	1,550,647	1,183,367
2020	1,198,231	798,755
2019	762,957	677,205
2018	658,383	638,690
Prior	2,355,925	2,001,549
Revolving loans amortized cost basis	891,809	904,441
Revolving loans converted to term loans	62,014	63,588
Total	8,774,136	7,887,713
Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	1,036,553	1,140,847
2021	1,225,714	984,337
2020	998,432	608,538
2019	602,166	557,498
2018	547,096	532,629
Prior	2,056,095	1,755,641
Revolving loans amortized cost basis	179,228	169,762
Revolving loans converted to term loans	39,961	40,478
Total	6,685,245	5,789,730
Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	17,931	10,511
2021	21,612	15,896
2020	14,409	7,236
2019	0	3,359
2018	4,794	0
Prior	0	0
Revolving loans amortized cost basis	17,749	25,262
Revolving loans converted to term loans	0	0
Total	76,495	62,264
SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	52,986	70,929
2021	56,165	36,468
2020	35,623	11,129
2019	12,905	36,853
2018	31,798	46,652
Prior	107,133	86,569
Revolving loans amortized cost basis	54	0
Revolving loans converted to term loans	0	0
Total	296,664	288,600
SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	183,614
2021	13,284	2,971
2020	4,064	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	17,348	186,585
Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	121,267	147,294
2021	148,123	83,879
2020	88,519	127,376
2019	105,860	57,798
2018	52,183	33,354
Prior	95,247	74,101
Revolving loans amortized cost basis	329,627	279,019
Revolving loans converted to term loans	11,405	10,242
Total	952,231	813,063
Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	2,318	2,808
2021	6,902	942
2020	1,713	1,285
2019	926	1,072
2018	569	95
Prior	1,466	295
Revolving loans amortized cost basis	302,856	371,291
Revolving loans converted to term loans	6,355	8,431
Total	323,105	386,219
Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	143	9,310
2021	27,134	7,666
2020	7,029	0
2019	4,370	279
2018	4,944	9,528
Prior	33,036	19,150
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	76,656	45,933
SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	55,028	48,821
2021	47,136	49,261
2020	47,005	41,776
2019	35,651	19,877
2018	16,842	16,046
Prior	61,594	64,017
Revolving loans amortized cost basis	0	451
Revolving loans converted to term loans	390	405
Total	263,646	240,654
Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	7,944	5,984
2021	4,577	1,947
2020	1,437	1,415
2019	1,079	469
2018	157	386
Prior	1,354	1,776
Revolving loans amortized cost basis	62,295	58,656
Revolving loans converted to term loans	3,903	4,032
Total	82,746	74,665
Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	1,289,741	1,613,286
2021	1,534,684	1,160,790
2020	1,169,824	780,690
2019	738,760	646,886
2018	622,524	581,735
Prior	2,254,339	1,939,076
Revolving loans amortized cost basis	868,295	872,585
Revolving loans converted to term loans	51,107	44,388
Total	8,529,274	7,639,436
Pass [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	1,036,048	1,137,714
2021	1,211,127	963,697
2020	972,387	591,202
2019	581,832	534,468
2018	522,728	484,721
Prior	1,963,428	1,704,267
Revolving loans amortized cost basis	177,910	156,841
Revolving loans converted to term loans	39,961	33,564
Total	6,505,421	5,606,474
Pass [Member] \| Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	17,931	10,511
2021	21,612	15,896
2020	14,409	7,236
2019	0	0
2018	0	0
Prior	0	0
Revolving loans amortized cost basis	17,749	25,262
Revolving loans converted to term loans	0	0
Total	71,701	58,905
Pass [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	52,986	70,929
2021	56,165	36,468
2020	35,527	11,129
2019	11,580	36,068
2018	29,886	38,504
Prior	100,265	78,527
Revolving loans amortized cost basis	54	0
Revolving loans converted to term loans	0	0
Total	286,463	271,625
Pass [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	183,614
2021	13,284	2,969
2020	4,064	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	17,348	186,583
Pass [Member] \| Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	117,792	145,494
2021	147,378	81,944
2020	87,201	126,647
2019	103,322	54,690
2018	47,588	32,455
Prior	94,924	73,600
Revolving loans amortized cost basis	315,146	267,659
Revolving loans converted to term loans	8,217	6,992
Total	921,568	789,481
Pass [Member] \| Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	1,869	1,756
2021	6,902	942
2020	1,713	1,285
2019	926	1,035
2018	379	95
Prior	1,254	295
Revolving loans amortized cost basis	295,737	364,312
Revolving loans converted to term loans	0	454
Total	308,780	370,174
Pass [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	143	9,310
2021	27,134	7,666
2020	7,029	0
2019	4,370	279
2018	4,944	9,528
Prior	32,549	18,811
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	76,169	45,594
Pass [Member] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	55,028	48,813
2021	47,136	49,261
2020	46,057	41,776
2019	35,651	19,877
2018	16,842	16,046
Prior	60,579	61,965
Revolving loans amortized cost basis	0	451
Revolving loans converted to term loans	0	0
Total	261,293	238,189
Pass [Member] \| Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	7,944	5,145
2021	3,946	1,947
2020	1,437	1,415
2019	1,079	469
2018	157	386
Prior	1,340	1,611
Revolving loans amortized cost basis	61,699	58,060
Revolving loans converted to term loans	2,929	3,378
Total	80,531	72,411
Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	4,429	6,588
2021	12,442	22,569
2020	11,822	14,604
2019	23,215	20,852
2018	30,954	47,712
Prior	79,788	47,260
Revolving loans amortized cost basis	15,754	23,909
Revolving loans converted to term loans	2,807	8,681
Total	181,211	192,175
Special Mention [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	505	3,133
2021	11,066	20,640
2020	10,234	14,477
2019	19,905	16,097
2018	24,272	43,262
Prior	77,113	44,045
Revolving loans amortized cost basis	1,318	6,970
Revolving loans converted to term loans	0	6,800
Total	144,413	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	4,794	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	4,794	3,359
Special Mention [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	96	0
2019	1,325	0
2018	1,341	4,056
Prior	2,354	2,700
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	5,116	6,756
Special Mention [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
Special Mention [Member] \| Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	3,475	1,556
2021	745	1,929
2020	544	127
2019	1,985	1,396
2018	486	394
Prior	20	26
Revolving loans amortized cost basis	12,548	9,369
Revolving loans converted to term loans	1,855	177
Total	21,658	14,974
Special Mention [Member] \| Dairy And Livestock And Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	449	1,052
2021	0	0
2020	0	0
2019	0	0
2018	61	0
Prior	0	0
Revolving loans amortized cost basis	1,297	6,979
Revolving loans converted to term loans	952	1,301
Total	2,759	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	301	339
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	301	339
Special Mention [Member] \| SFR mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	8
2021	0	0
2020	948	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	948	8
Special Mention [Member] \| Consumer Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	839
2021	631	0
2020	0	0
2019	0	0
2018	0	0
Prior	0	150
Revolving loans amortized cost basis	591	591
Revolving loans converted to term loans	0	403
Total	1,222	1,983
Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	244
2021	3,521	8
2020	16,585	3,461
2019	982	9,467
2018	4,905	9,243
Prior	21,798	15,213
Revolving loans amortized cost basis	7,760	7,947
Revolving loans converted to term loans	8,100	10,519
Total	63,651	56,102
Substandard [Member] \| Commercial real estate loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	3,521	0
2020	15,811	2,859
2019	429	6,933
2018	96	4,646
Prior	15,554	7,329
Revolving loans amortized cost basis	0	5,951
Revolving loans converted to term loans	0	114
Total	35,411	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	571	4,092
Prior	4,514	5,342
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	5,085	10,219
Substandard [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	2
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	2
Substandard [Member] \| Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	244
2021	0	6
2020	774	602
2019	553	1,712
2018	4,109	505
Prior	303	475
Revolving loans amortized cost basis	1,933	1,991
Revolving loans converted to term loans	1,333	3,073
Total	9,005	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	129	0
Prior	212	0
Revolving loans amortized cost basis	5,822	0
Revolving loans converted to term loans	5,403	6,676
Total	11,566	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	186	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	186	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	1,015	2,052
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	390	405
Total	1,405	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	14	15
Revolving loans amortized cost basis	5	5
Revolving loans converted to term loans	974	251
Total	993	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