Loans and the Allowance for Credit Losses - Summary of Amortized Cost Basis Loan Balances by Year of Origination and Credit Quality Indicator (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 11,638,461	$ 10,702,728
30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	15,152	11,222
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,729	6,621
90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	25,302	30,986
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	12,828	10,798
Amortized Cost Basis by Origination Year 2022	1,959	1,535
Amortized Cost Basis by Origination Year 2021	1,568	1,885
Amortized Cost Basis by Origination Year 2020	2,449	1,984
Amortized Cost Basis by Origination Year 2019	1,964	1,467
Amortized Cost Basis by Origination Year, Prior to 2018	26,482	29,251
Revolving Loans	685,163	646,706
Revolving Loans Converted to Term	1,806	1,439
Total loans	734,219	695,065
Home Equity [Member] | Current [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	12,675	10,718
Amortized Cost Basis by Origination Year 2022	1,235	1,459
Amortized Cost Basis by Origination Year 2021	1,467	1,133
Amortized Cost Basis by Origination Year 2020	1,571	1,774
Amortized Cost Basis by Origination Year 2019	1,614	1,088
Amortized Cost Basis by Origination Year, Prior to 2018	22,484	25,203
Revolving Loans	681,848	644,430
Revolving Loans Converted to Term	1,399	957
Total loans	724,293	686,762
Home Equity [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	34	80
Amortized Cost Basis by Origination Year 2022	193	61
Amortized Cost Basis by Origination Year 2021	85	180
Amortized Cost Basis by Origination Year 2020	73	67
Amortized Cost Basis by Origination Year 2019	44	34
Amortized Cost Basis by Origination Year, Prior to 2018	947	1,165
Revolving Loans	3,315	2,260
Revolving Loans Converted to Term		38
Total loans	4,691	3,885
Home Equity [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	119
Amortized Cost Basis by Origination Year 2022	318	15
Amortized Cost Basis by Origination Year 2021	16
Amortized Cost Basis by Origination Year 2020	68	50
Amortized Cost Basis by Origination Year 2019	76	88
Amortized Cost Basis by Origination Year, Prior to 2018	524	458
Revolving Loans Converted to Term	77	10
Total loans	1,198	621
Home Equity [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2022	213
Amortized Cost Basis by Origination Year 2021		572
Amortized Cost Basis by Origination Year 2020	737	93
Amortized Cost Basis by Origination Year 2019	230	257
Amortized Cost Basis by Origination Year, Prior to 2018	2,527	2,425
Revolving Loans		16
Revolving Loans Converted to Term	330	434
Total loans	4,037	3,797
Home Equity [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2022	139
Amortized Cost Basis by Origination Year 2021	57
Amortized Cost Basis by Origination Year 2020	29
Amortized Cost Basis by Origination Year 2019	79
Amortized Cost Basis by Origination Year, Prior to 2018	615	310
Revolving Loans	6
Revolving Loans Converted to Term		48
Total loans	925	358
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,565,448	6,061,344
Commercial Real Estate [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,416	2,147
Commercial Real Estate [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,627	1,241
Commercial Real Estate [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	10,594	16,378
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	277,790	541,659
Amortized Cost Basis by Origination Year 2022	430,634	557,370
Amortized Cost Basis by Origination Year 2021	445,356	211,845
Amortized Cost Basis by Origination Year 2020	185,480	97,510
Amortized Cost Basis by Origination Year 2019	86,412	52,254
Amortized Cost Basis by Origination Year, Prior to 2018	464,727	489,164
Revolving Loans Converted to Term	548,175	190,782
Total loans	2,438,574	2,140,584
Residential Real Estate [Member] | Current [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	277,790	541,659
Amortized Cost Basis by Origination Year 2022	429,835	556,928
Amortized Cost Basis by Origination Year 2021	445,322	211,496
Amortized Cost Basis by Origination Year 2020	185,139	97,160
Amortized Cost Basis by Origination Year 2019	86,149	52,135
Amortized Cost Basis by Origination Year, Prior to 2018	456,818	478,977
Revolving Loans Converted to Term	548,147	190,740
Total loans	2,429,200	2,129,095
Residential Real Estate [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year, Prior to 2018	1,572	853
Total loans	1,572	853
Residential Real Estate [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2022		442
Amortized Cost Basis by Origination Year 2021		349
Amortized Cost Basis by Origination Year 2020	341	65
Amortized Cost Basis by Origination Year, Prior to 2018	2,130	2,680
Total loans	2,471	3,536
Residential Real Estate [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2022	799
Amortized Cost Basis by Origination Year 2021	34
Amortized Cost Basis by Origination Year 2020		285
Amortized Cost Basis by Origination Year 2019	263	119
Amortized Cost Basis by Origination Year, Prior to 2018	4,207	6,654
Revolving Loans Converted to Term	28	42
Total loans	5,331	7,100
Residential Real Estate [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2019	5	6
Amortized Cost Basis by Origination Year, Prior to 2018	387	494
Total loans	392	500
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	85,480	86,164
Amortized Cost Basis by Origination Year 2022	60,006	37,561
Amortized Cost Basis by Origination Year 2021	22,853	25,722
Amortized Cost Basis by Origination Year 2020	13,707	25,773
Amortized Cost Basis by Origination Year 2019	11,134	8,617
Amortized Cost Basis by Origination Year, Prior to 2018	12,429	16,690
Revolving Loans	23,948	25,786
Revolving Loans Converted to Term	4	27
Total loans	229,561	226,340
Consumer [Member] | Current [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	84,526	84,817
Amortized Cost Basis by Origination Year 2022	57,661	36,123
Amortized Cost Basis by Origination Year 2021	21,592	25,071
Amortized Cost Basis by Origination Year 2020	13,189	25,535
Amortized Cost Basis by Origination Year 2019	10,958	8,488
Amortized Cost Basis by Origination Year, Prior to 2018	12,143	16,337
Revolving Loans	23,916	25,755
Revolving Loans Converted to Term	4	27
Total loans	223,989	222,153
Consumer [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	699	980
Amortized Cost Basis by Origination Year 2022	1,526	937
Amortized Cost Basis by Origination Year 2021	952	488
Amortized Cost Basis by Origination Year 2020	343	159
Amortized Cost Basis by Origination Year 2019	162	98
Amortized Cost Basis by Origination Year, Prior to 2018	119	217
Revolving Loans	32	31
Total loans	3,833	2,910
Consumer [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	191	184
Amortized Cost Basis by Origination Year 2022	616	293
Amortized Cost Basis by Origination Year 2021	195	94
Amortized Cost Basis by Origination Year 2020	112	47
Amortized Cost Basis by Origination Year 2019	5	29
Amortized Cost Basis by Origination Year, Prior to 2018	59	57
Total loans	1,178	704
Consumer [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	64	183
Amortized Cost Basis by Origination Year 2022	203	208
Amortized Cost Basis by Origination Year 2021	114	69
Amortized Cost Basis by Origination Year 2020	63	32
Amortized Cost Basis by Origination Year 2019	9	2
Amortized Cost Basis by Origination Year, Prior to 2018	108	79
Total loans	561	573
Consumer [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	251	769
Amortized Cost Basis by Origination Year 2022	1,921	1,237
Amortized Cost Basis by Origination Year 2021	901	624
Amortized Cost Basis by Origination Year 2020	301	333
Amortized Cost Basis by Origination Year 2019	100	186
Amortized Cost Basis by Origination Year, Prior to 2018	247	326
Revolving Loans	4
Revolving Loans Converted to Term		1
Total loans	3,725	3,476
Commercial Real Estate - Land and Construction [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2019		73
Revolving Loans Converted to Term	222
Total loans	222	73
Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	290,954	160,328
Amortized Cost Basis by Origination Year 2022	349,549	136,396
Amortized Cost Basis by Origination Year 2021	145,043	144,172
Amortized Cost Basis by Origination Year 2020	54,172	155,141
Amortized Cost Basis by Origination Year 2019	48,655	61,847
Amortized Cost Basis by Origination Year, Prior to 2018	35,942	51,536
Revolving Loans	82,587	117,237
Revolving Loans Converted to Term	48,963	117,230
Total loans	1,055,865	943,887
Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans		910
Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans		741
Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	290,954	159,769
Amortized Cost Basis by Origination Year 2022	349,549	136,131
Amortized Cost Basis by Origination Year 2021	145,043	138,171
Amortized Cost Basis by Origination Year 2020	54,172	155,141
Amortized Cost Basis by Origination Year 2019	48,655	61,823
Amortized Cost Basis by Origination Year, Prior to 2018	35,917	51,381
Revolving Loans	82,288	117,237
Revolving Loans Converted to Term	46,781	92,151
Total loans	1,053,359	911,804
Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member] | Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023		559
Amortized Cost Basis by Origination Year 2022		265
Amortized Cost Basis by Origination Year 2019		24
Amortized Cost Basis by Origination Year, Prior to 2018	16	31
Revolving Loans	299
Revolving Loans Converted to Term	2,182	450
Total loans	2,497	1,329
Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member] | Classified - substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2021		6,001
Amortized Cost Basis by Origination Year, Prior to 2018	9	124
Revolving Loans Converted to Term		24,629
Total loans	9	30,754
Commercial Real Estate - Improved Property [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2021	372	128
Amortized Cost Basis by Origination Year 2020		100
Amortized Cost Basis by Origination Year 2019		3
Amortized Cost Basis by Origination Year, Prior to 2018	1,505	564
Total loans	1,877	795
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	496,063	1,093,538
Amortized Cost Basis by Origination Year 2022	1,093,322	621,217
Amortized Cost Basis by Origination Year 2021	612,401	616,815
Amortized Cost Basis by Origination Year 2020	588,343	551,152
Amortized Cost Basis by Origination Year 2019	543,180	395,192
Amortized Cost Basis by Origination Year, Prior to 2018	1,787,604	1,666,522
Revolving Loans	105,840	73,427
Revolving Loans Converted to Term	282,830	99,594
Total loans	5,509,583	5,117,457
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,416	2,147
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,627	331
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	10,594	15,637
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	494,142	1,082,984
Amortized Cost Basis by Origination Year 2022	1,076,535	620,205
Amortized Cost Basis by Origination Year 2021	603,354	613,663
Amortized Cost Basis by Origination Year 2020	581,540	528,004
Amortized Cost Basis by Origination Year 2019	514,523	371,880
Amortized Cost Basis by Origination Year, Prior to 2018	1,706,804	1,551,478
Revolving Loans	103,467	72,327
Revolving Loans Converted to Term	257,029	99,594
Total loans	5,337,394	4,940,135
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member] | Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023		10,554
Amortized Cost Basis by Origination Year 2022	16,270	354
Amortized Cost Basis by Origination Year 2021	8,630	2,877
Amortized Cost Basis by Origination Year 2020	4,387	7,659
Amortized Cost Basis by Origination Year 2019	5,185	13,551
Amortized Cost Basis by Origination Year, Prior to 2018	44,861	85,332
Revolving Loans	2,373	1,066
Revolving Loans Converted to Term	25,767
Total loans	107,473	121,393
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member] | Classified - substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	1,921
Amortized Cost Basis by Origination Year 2022	517	658
Amortized Cost Basis by Origination Year 2021	417	275
Amortized Cost Basis by Origination Year 2020	2,416	15,489
Amortized Cost Basis by Origination Year 2019	23,472	9,761
Amortized Cost Basis by Origination Year, Prior to 2018	35,939	29,712
Revolving Loans		34
Revolving Loans Converted to Term	34
Total loans	64,716	55,929
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	239,554	281,520
Amortized Cost Basis by Origination Year 2022	235,503	189,206
Amortized Cost Basis by Origination Year 2021	140,482	118,136
Amortized Cost Basis by Origination Year 2020	80,591	82,577
Amortized Cost Basis by Origination Year 2019	47,418	104,021
Amortized Cost Basis by Origination Year, Prior to 2018	286,268	237,440
Revolving Loans	567,823	534,745
Revolving Loans Converted to Term	73,020	31,750
Total loans	1,670,659	1,579,395
Commercial and Industrial [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	640	1,427
Commercial and Industrial [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,255	519
Commercial and Industrial [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,779	3,138
Commercial and Industrial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	238,427	280,510
Amortized Cost Basis by Origination Year 2022	234,520	184,805
Amortized Cost Basis by Origination Year 2021	136,998	116,890
Amortized Cost Basis by Origination Year 2020	78,836	72,142
Amortized Cost Basis by Origination Year 2019	39,259	103,660
Amortized Cost Basis by Origination Year, Prior to 2018	252,826	232,062
Revolving Loans	541,400	526,025
Revolving Loans Converted to Term	64,417	22,206
Total loans	1,586,683	1,538,300
Commercial and Industrial [Member] | Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	1,094	917
Amortized Cost Basis by Origination Year 2022	834	1,192
Amortized Cost Basis by Origination Year 2021	3,169	270
Amortized Cost Basis by Origination Year 2020	1,490	8,278
Amortized Cost Basis by Origination Year 2019	7,334	264
Amortized Cost Basis by Origination Year, Prior to 2018	31,526	2,524
Revolving Loans	20,626	7,654
Revolving Loans Converted to Term	7,131	4,124
Total loans	73,204	25,223
Commercial and Industrial [Member] | Classified - substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	33	93
Amortized Cost Basis by Origination Year 2022	149	3,209
Amortized Cost Basis by Origination Year 2021	315	976
Amortized Cost Basis by Origination Year 2020	265	2,157
Amortized Cost Basis by Origination Year 2019	825	97
Amortized Cost Basis by Origination Year, Prior to 2018	1,916	2,854
Revolving Loans	5,797	1,066
Revolving Loans Converted to Term	1,472	5,420
Total loans	10,772	15,872
Commercial and Industrial [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	98
Amortized Cost Basis by Origination Year 2022	205	16
Amortized Cost Basis by Origination Year 2021	603	234
Amortized Cost Basis by Origination Year 2020	353	275
Amortized Cost Basis by Origination Year 2019	20	70
Amortized Cost Basis by Origination Year, Prior to 2018	463	182
Revolving Loans Converted to Term	541	291
Total loans	$ 2,283	$ 1,068