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	6 Months Ended
Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
2023	$ 414,408	$ 1,683,162
2022	1,647,122	1,512,519
2021	1,460,142	1,178,645
2020	1,161,237	744,349
2019	702,989	633,929
Prior	2,656,391	2,265,644
Revolving loans amortized cost basis	805,922	1,002,474
Revolving loans converted to term loans	59,186	58,670
Total	8,907,397	9,079,392
Gross charge-off prior	198
Gross charge-off total	198
Commercial Real Estate Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	309,443	1,367,018
2022	1,353,439	1,209,404
2021	1,184,104	984,873
2020	964,716	592,100
2019	574,933	528,353
Prior	2,314,136	1,987,303
Revolving loans amortized cost basis	163,318	176,281
Revolving loans converted to term loans	40,006	39,616
Total	6,904,095	6,884,948
Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	331	17,203
2022	14,592	26,689
2021	27,121	16,578
2020	8,055	0
2019	0	4,951
Prior	0	0
Revolving loans amortized cost basis	18,737	22,850
Revolving loans converted to term loans	0	0
Total	68,836	88,271
SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	9,596	60,623
2022	50,938	54,781
2021	53,763	35,243
2020	34,661	8,781
2019	8,509	30,735
Prior	121,387	99,719
Revolving loans amortized cost basis	50	1,026
Revolving loans converted to term loans	0	0
Total	278,904	290,908
Gross charge-off prior	181
Gross charge-off total	181
SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	2,215	3,572
2020	2,802	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	5,017	9,087
Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	81,889	159,214
2022	154,640	135,923
2021	117,011	81,950
2020	96,835	103,844
2019	84,405	48,817
Prior	113,425	85,910
Revolving loans amortized cost basis	294,697	323,945
Revolving loans converted to term loans	13,340	9,080
Total	956,242	948,683
Gross charge-off prior	16
Gross charge-off total	16
Dairy and Livestock and Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	776	1,248
2022	0	2,318
2021	1,568	1,555
2020	1,067	786
2019	231	210
Prior	950	741
Revolving loans amortized cost basis	290,867	419,199
Revolving loans converted to term loans	2,788	7,507
Total	298,247	433,564
Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	6,442
2022	6,004	26,858
2021	26,720	6,814
2020	6,433	4,327
2019	4,324	4,948
Prior	34,386	31,737
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	77,867	81,126
SFR Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	10,187	63,761
2022	62,119	46,748
2021	44,114	46,762
2020	45,700	33,585
2019	29,812	15,836
Prior	70,914	58,944
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	355	388
Total	263,201	266,024
Consumer and Other Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	2,186	7,653
2022	5,390	4,283
2021	3,526	1,298
2020	968	0
2019	775	79
Prior	1,193	1,290
Revolving loans amortized cost basis	38,253	59,173
Revolving loans converted to term loans	2,697	2,079
Total	54,988	76,781
Gross charge-off prior	1
Gross charge-off total	1
Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	405,541	1,674,387
2022	1,642,448	1,499,083
2021	1,448,692	1,149,567
2020	1,126,038	690,504
2019	645,555	599,162
Prior	2,518,782	2,163,284
Revolving loans amortized cost basis	781,945	963,645
Revolving loans converted to term loans	47,361	48,948
Total	8,616,362	8,788,580
Pass [Member] \| Commercial Real Estate Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	306,867	1,363,733
2022	1,349,741	1,197,290
2021	1,174,063	957,965
2020	931,868	542,827
2019	525,101	506,613
Prior	2,187,525	1,889,478
Revolving loans amortized cost basis	161,223	175,373
Revolving loans converted to term loans	40,006	39,616
Total	6,676,394	6,672,895
Pass [Member] \| Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	331	17,203
2022	14,592	26,689
2021	27,121	16,578
2020	8,055	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	18,737	22,850
Revolving loans converted to term loans	0	0
Total	68,836	83,320
Pass [Member] \| SBA [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	9,596	60,623
2022	50,938	54,781
2021	53,763	35,243
2020	34,661	7,460
2019	6,447	28,886
Prior	116,511	96,473
Revolving loans amortized cost basis	50	1,026
Revolving loans converted to term loans	0	0
Total	271,966	284,492
Pass [Member] \| SBA - Paycheck Protection Program (PPP) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	2,215	3,572
2020	2,802	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	5,017	9,087
Pass [Member] \| Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	75,598	154,765
2022	153,664	135,162
2021	115,911	80,763
2020	95,413	101,192
2019	79,161	42,731
Prior	108,792	85,406
Revolving loans amortized cost basis	288,660	305,589
Revolving loans converted to term loans	5,915	7,775
Total	923,114	913,383
Pass [Member] \| Dairy and Livestock and Agribusiness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	776	207
2022	0	0
2021	1,568	1,515
2020	1,067	187
2019	134	69
Prior	172	0
Revolving loans amortized cost basis	275,070	400,229
Revolving loans converted to term loans	343	450
Total	279,130	405,603
Pass [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	6,442
2022	6,004	26,858
2021	26,720	6,814
2020	6,433	4,327
2019	4,324	4,948
Prior	34,163	31,292
Revolving loans amortized cost basis	0
Revolving loans converted to term loans	0
Total	77,644
Pass [Member] \| SFR Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	10,187	63,761
2022	62,119	46,748
2021	44,114	45,819
2020	44,771	33,585
2019	29,613	15,836
Prior	70,438	58,730
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	261,242	264,479
Pass [Member] \| Consumer and Other Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	2,186	7,653
2022	5,390	3,722
2021	3,217	1,298
2020	968	0
2019	775	79
Prior	1,181	1,277
Revolving loans amortized cost basis	38,205	58,578
Revolving loans converted to term loans	1,097	1,107
Total	53,019	74,640
Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	8,867	7,240
2022	4,211	13,436
2021	11,450	12,686
2020	19,797	36,589
2019	40,702	28,398
Prior	110,128	78,625
Revolving loans amortized cost basis	9,130	33,783
Revolving loans converted to term loans	8,916	1,397
Total	213,201	212,154
Special Mention [Member] \| Commercial Real Estate Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	2,576	3,285
2022	3,235	12,114
2021	10,041	11,284
2020	18,081	32,976
2019	33,490	21,646
Prior	103,542	76,290
Revolving loans amortized cost basis	1,296	908
Revolving loans converted to term loans	0	0
Total	172,261	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	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	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	2,062	1,293
Prior	2,763	2,065
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	4,825	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	6,291	3,955
2022	976	761
2021	1,100	459
2020	787	1,693
2019	4,854	462
Prior	3,318	8
Revolving loans amortized cost basis	3,379	15,156
Revolving loans converted to term loans	6,432	544
Total	27,137	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
2019	97	46
Prior	15	0
Revolving loans amortized cost basis	4,413	17,129
Revolving loans converted to term loans	1,651	853
Total	6,176	18,627
Special Mention [Member] \| Municipal Lease Finance Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	223	262
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	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	929	0
2019	199	0
Prior	267	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	1,395	943
Special Mention [Member] \| Consumer and Other Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	561
2021	309	0
2020	0	0
2019	0	0
Prior	0	0
Revolving loans amortized cost basis	42	590
Revolving loans converted to term loans	833	0
Total	1,184	1,151
Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	1,535
2022	463	0
2021	0	16,392
2020	15,402	17,256
2019	16,732	6,369
Prior	27,481	23,735
Revolving loans amortized cost basis	14,847	5,046
Revolving loans converted to term loans	2,909	8,325
Total	77,834	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	0	16,297
2019	0	94
Prior	0	21,535
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	55,440	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	2,113	1,181
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	2,113	1,737
Substandard [Member] \| SBA - Paycheck Protection Program (PPP) [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
Substandard [Member] \| Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	494
2022	0	0
2021	0	728
2020	635	959
2019	390	5,624
Prior	1,315	496
Revolving loans amortized cost basis	2,658	3,200
Revolving loans converted to term loans	993	761
Total	5,991	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	763	113
Revolving loans amortized cost basis	11,384	1,841
Revolving loans converted to term loans	794	6,204
Total	12,941	9,334
Substandard [Member] \| Municipal Lease Finance Receivables [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	183
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	0	0
Total	0	183
Substandard [Member] \| SFR Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	209	214
Revolving loans amortized cost basis	0	0
Revolving loans converted to term loans	355	388
Total	564	602
Substandard [Member] \| Consumer and Other 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	12	13
Revolving loans amortized cost basis	6	5
Revolving loans converted to term loans	767	972
Total	785	990
Doubtful & Loss [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 & Loss [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 & Loss [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 & Loss [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 & Loss [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

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