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	Jun. 30, 2024	Dec. 31, 2023
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 12,257,511	$ 11,638,461
30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	11,656	15,152
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,893	9,729
90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	32,559	25,302
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	11,124	12,828
Amortized Cost Basis by Origination Year 2023	2,114	1,959
Amortized Cost Basis by Origination Year 2022	3,237	1,568
Amortized Cost Basis by Origination Year 2021	1,363	2,449
Amortized Cost Basis by Origination Year 2020	2,914	1,964
Amortized Cost Basis by Origination Year, Prior to 2019	25,629	26,482
Revolving Loans	722,064	685,163
Revolving Loans Converted to Term	2,154	1,806
Total loans	770,599	734,219
Home Equity [Member] | Current [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	11,124	12,675
Amortized Cost Basis by Origination Year 2023	1,221	1,235
Amortized Cost Basis by Origination Year 2022	2,297	1,467
Amortized Cost Basis by Origination Year 2021	961	1,571
Amortized Cost Basis by Origination Year 2020	1,961	1,614
Amortized Cost Basis by Origination Year, Prior to 2019	21,870	22,484
Revolving Loans	719,968	681,848
Revolving Loans Converted to Term	1,362	1,399
Total loans	760,764	724,293
Home Equity [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024		34
Amortized Cost Basis by Origination Year 2023	17	193
Amortized Cost Basis by Origination Year 2022	414	85
Amortized Cost Basis by Origination Year 2021	65	73
Amortized Cost Basis by Origination Year 2020	239	44
Amortized Cost Basis by Origination Year, Prior to 2019	701	947
Revolving Loans	2,096	3,315
Revolving Loans Converted to Term	130
Total loans	3,662	4,691
Home Equity [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024		119
Amortized Cost Basis by Origination Year 2023	146	318
Amortized Cost Basis by Origination Year 2022	175	16
Amortized Cost Basis by Origination Year 2021	89	68
Amortized Cost Basis by Origination Year 2020		76
Amortized Cost Basis by Origination Year, Prior to 2019	668	524
Revolving Loans Converted to Term	347	77
Total loans	1,425	1,198
Home Equity [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	730	213
Amortized Cost Basis by Origination Year 2022	351
Amortized Cost Basis by Origination Year 2021	248	737
Amortized Cost Basis by Origination Year 2020	714	230
Amortized Cost Basis by Origination Year, Prior to 2019	2,390	2,527
Revolving Loans Converted to Term	315	330
Total loans	4,748	4,037
Home Equity [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023	44	139
Amortized Cost Basis by Origination Year 2022	105	57
Amortized Cost Basis by Origination Year 2021	16	29
Amortized Cost Basis by Origination Year 2020	35	79
Amortized Cost Basis by Origination Year, Prior to 2019	171	615
Revolving Loans	20	6
Revolving Loans Converted to Term	22
Total loans	413	925
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,998,888	6,565,448
Commercial Real Estate [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,415	4,416
Commercial Real Estate [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,119	3,627
Commercial Real Estate [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	15,918	10,594
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	97,366	277,790
Amortized Cost Basis by Origination Year 2023	261,988	430,634
Amortized Cost Basis by Origination Year 2022	362,299	445,356
Amortized Cost Basis by Origination Year 2021	417,196	185,480
Amortized Cost Basis by Origination Year 2020	178,983	86,412
Amortized Cost Basis by Origination Year, Prior to 2019	517,523	464,727
Revolving Loans Converted to Term	671,602	548,175
Total loans	2,506,957	2,438,574
Residential Real Estate [Member] | Current [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	97,366	277,790
Amortized Cost Basis by Origination Year 2023	261,988	429,835
Amortized Cost Basis by Origination Year 2022	361,520	445,322
Amortized Cost Basis by Origination Year 2021	417,068	185,139
Amortized Cost Basis by Origination Year 2020	178,481	86,149
Amortized Cost Basis by Origination Year, Prior to 2019	509,163	456,818
Revolving Loans Converted to Term	669,229	548,147
Total loans	2,494,815	2,429,200
Residential Real Estate [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year, Prior to 2019	1,123	1,572
Total loans	1,123	1,572
Residential Real Estate [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2022	125
Amortized Cost Basis by Origination Year 2021	94	341
Amortized Cost Basis by Origination Year 2020	337
Amortized Cost Basis by Origination Year, Prior to 2019	2,672	2,130
Revolving Loans Converted to Term	759
Total loans	3,987	2,471
Residential Real Estate [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2023		799
Amortized Cost Basis by Origination Year 2022	654	34
Amortized Cost Basis by Origination Year 2021	34
Amortized Cost Basis by Origination Year 2020	165	263
Amortized Cost Basis by Origination Year, Prior to 2019	4,565	4,207
Revolving Loans Converted to Term	1,614	28
Total loans	7,032	5,331
Residential Real Estate [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2020		5
Amortized Cost Basis by Origination Year, Prior to 2019	214	387
Revolving Loans Converted to Term	58
Total loans	272	392
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	34,360	85,480
Amortized Cost Basis by Origination Year 2023	70,051	60,006
Amortized Cost Basis by Origination Year 2022	48,825	22,853
Amortized Cost Basis by Origination Year 2021	17,369	13,707
Amortized Cost Basis by Origination Year 2020	9,285	11,134
Amortized Cost Basis by Origination Year, Prior to 2019	15,275	12,429
Revolving Loans	25,422	23,948
Revolving Loans Converted to Term	1	4
Total loans	220,588	229,561
Consumer [Member] | Current [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	34,018	84,526
Amortized Cost Basis by Origination Year 2023	68,563	57,661
Amortized Cost Basis by Origination Year 2022	47,131	21,592
Amortized Cost Basis by Origination Year 2021	16,596	13,189
Amortized Cost Basis by Origination Year 2020	8,993	10,958
Amortized Cost Basis by Origination Year, Prior to 2019	14,813	12,143
Revolving Loans	25,387	23,916
Revolving Loans Converted to Term		4
Total loans	215,501	223,989
Consumer [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	269	699
Amortized Cost Basis by Origination Year 2023	1,031	1,526
Amortized Cost Basis by Origination Year 2022	1,160	952
Amortized Cost Basis by Origination Year 2021	643	343
Amortized Cost Basis by Origination Year 2020	200	162
Amortized Cost Basis by Origination Year, Prior to 2019	286	119
Revolving Loans	35	32
Revolving Loans Converted to Term	1
Total loans	3,625	3,833
Consumer [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	71	191
Amortized Cost Basis by Origination Year 2023	287	616
Amortized Cost Basis by Origination Year 2022	422	195
Amortized Cost Basis by Origination Year 2021	111	112
Amortized Cost Basis by Origination Year 2020	43	5
Amortized Cost Basis by Origination Year, Prior to 2019	94	59
Total loans	1,028	1,178
Consumer [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	2	64
Amortized Cost Basis by Origination Year 2023	170	203
Amortized Cost Basis by Origination Year 2022	112	114
Amortized Cost Basis by Origination Year 2021	19	63
Amortized Cost Basis by Origination Year 2020	49	9
Amortized Cost Basis by Origination Year, Prior to 2019	82	108
Total loans	434	561
Consumer [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024		251
Amortized Cost Basis by Origination Year 2023	560	1,921
Amortized Cost Basis by Origination Year 2022	860	901
Amortized Cost Basis by Origination Year 2021	308	301
Amortized Cost Basis by Origination Year 2020	115	100
Amortized Cost Basis by Origination Year, Prior to 2019	137	247
Revolving Loans		4
Total loans	1,980	3,725
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 2023	813
Revolving Loans Converted to Term		222
Total loans	813	222
Commercial Real Estate - Land and Construction [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	79,862	290,954
Amortized Cost Basis by Origination Year 2023	349,374	349,549
Amortized Cost Basis by Origination Year 2022	336,084	145,043
Amortized Cost Basis by Origination Year 2021	91,369	54,172
Amortized Cost Basis by Origination Year 2020	23,345	48,655
Amortized Cost Basis by Origination Year, Prior to 2019	57,083	35,942
Revolving Loans	67,563	82,587
Revolving Loans Converted to Term	56,710	48,963
Total loans	1,061,390	1,055,865
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 2024	79,862	290,954
Amortized Cost Basis by Origination Year 2023	349,190	349,549
Amortized Cost Basis by Origination Year 2022	336,084	145,043
Amortized Cost Basis by Origination Year 2021	91,369	54,172
Amortized Cost Basis by Origination Year 2020	23,345	48,655
Amortized Cost Basis by Origination Year, Prior to 2019	57,058	35,917
Revolving Loans	67,265	82,288
Revolving Loans Converted to Term	54,566	46,781
Total loans	1,058,739	1,053,359
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, Prior to 2019	17	16
Revolving Loans	298	299
Revolving Loans Converted to Term	657	2,182
Total loans	972	2,497
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 2023	184
Amortized Cost Basis by Origination Year, Prior to 2019	8	9
Revolving Loans Converted to Term	1,487
Total loans	1,679	9
Commercial Real Estate - Improved Property [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2022		372
Amortized Cost Basis by Origination Year, Prior to 2019	815	1,505
Total loans	815	1,877
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	262,116	496,063
Amortized Cost Basis by Origination Year 2023	545,264	1,093,322
Amortized Cost Basis by Origination Year 2022	1,153,548	612,401
Amortized Cost Basis by Origination Year 2021	605,407	588,343
Amortized Cost Basis by Origination Year 2020	605,940	543,180
Amortized Cost Basis by Origination Year, Prior to 2019	2,151,455	1,787,604
Revolving Loans	184,196	105,840
Revolving Loans Converted to Term	429,572	282,830
Total loans	5,937,498	5,509,583
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,415	4,416
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,119	3,627
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	15,918	10,594
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	258,814	494,142
Amortized Cost Basis by Origination Year 2023	529,239	1,076,535
Amortized Cost Basis by Origination Year 2022	1,134,557	603,354
Amortized Cost Basis by Origination Year 2021	596,861	581,540
Amortized Cost Basis by Origination Year 2020	598,755	514,523
Amortized Cost Basis by Origination Year, Prior to 2019	2,054,008	1,706,804
Revolving Loans	181,757	103,467
Revolving Loans Converted to Term	401,693	257,029
Total loans	5,755,684	5,337,394
Commercial Real Estate - Improved Property [Member] | Commercial Real Estate [Member] | Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	3,302
Amortized Cost Basis by Origination Year 2023	14,165	16,270
Amortized Cost Basis by Origination Year 2022	13,200	8,630
Amortized Cost Basis by Origination Year 2021	8,135	4,387
Amortized Cost Basis by Origination Year 2020	3,549	5,185
Amortized Cost Basis by Origination Year, Prior to 2019	36,258	44,861
Revolving Loans	2,139	2,373
Revolving Loans Converted to Term	27,845	25,767
Total loans	108,593	107,473
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 2024		1,921
Amortized Cost Basis by Origination Year 2023	1,860	517
Amortized Cost Basis by Origination Year 2022	5,791	417
Amortized Cost Basis by Origination Year 2021	411	2,416
Amortized Cost Basis by Origination Year 2020	3,636	23,472
Amortized Cost Basis by Origination Year, Prior to 2019	61,189	35,939
Revolving Loans	300
Revolving Loans Converted to Term	34	34
Total loans	73,221	64,716
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	153,946	239,554
Amortized Cost Basis by Origination Year 2023	201,919	235,503
Amortized Cost Basis by Origination Year 2022	225,393	140,482
Amortized Cost Basis by Origination Year 2021	127,590	80,591
Amortized Cost Basis by Origination Year 2020	58,972	47,418
Amortized Cost Basis by Origination Year, Prior to 2019	300,709	286,268
Revolving Loans	617,003	567,823
Revolving Loans Converted to Term	74,947	73,020
Total loans	1,760,479	1,670,659
Commercial and Industrial [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	831	640
Commercial and Industrial [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,334	1,255
Commercial and Industrial [Member] | 90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,427	4,779
Commercial and Industrial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024	153,946	238,427
Amortized Cost Basis by Origination Year 2023	195,932	234,520
Amortized Cost Basis by Origination Year 2022	222,272	136,998
Amortized Cost Basis by Origination Year 2021	125,094	78,836
Amortized Cost Basis by Origination Year 2020	57,423	39,259
Amortized Cost Basis by Origination Year, Prior to 2019	261,606	252,826
Revolving Loans	598,810	541,400
Revolving Loans Converted to Term	66,496	64,417
Total loans	1,681,579	1,586,683
Commercial and Industrial [Member] | Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024		1,094
Amortized Cost Basis by Origination Year 2023	5,914	834
Amortized Cost Basis by Origination Year 2022	2,573	3,169
Amortized Cost Basis by Origination Year 2021	1,768	1,490
Amortized Cost Basis by Origination Year 2020	1,432	7,334
Amortized Cost Basis by Origination Year, Prior to 2019	37,694	31,526
Revolving Loans	13,199	20,626
Revolving Loans Converted to Term	7,476	7,131
Total loans	70,056	73,204
Commercial and Industrial [Member] | Classified - substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024		33
Amortized Cost Basis by Origination Year 2023	73	149
Amortized Cost Basis by Origination Year 2022	548	315
Amortized Cost Basis by Origination Year 2021	728	265
Amortized Cost Basis by Origination Year 2020	117	825
Amortized Cost Basis by Origination Year, Prior to 2019	1,409	1,916
Revolving Loans	4,994	5,797
Revolving Loans Converted to Term	975	1,472
Total loans	8,844	10,772
Commercial and Industrial [Member] | Current-period gross charge-offs [Member]
Financing Receivable, Recorded Investment [Line Items]
Amortized Cost Basis by Origination Year 2024		98
Amortized Cost Basis by Origination Year 2023	487	205
Amortized Cost Basis by Origination Year 2022	580	603
Amortized Cost Basis by Origination Year 2021	86	353
Amortized Cost Basis by Origination Year 2020	143	20
Amortized Cost Basis by Origination Year, Prior to 2019	325	463
Revolving Loans	1
Revolving Loans Converted to Term	4,450	541
Total loans	$ 6,072	$ 2,283