Loans and Allowance for Credit Losses - Schedule of Internal Risk-rating Categories (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	$ 655,416		$ 655,416		$ 1,685,825
2023	1,655,892		1,655,892		3,116,426
2022	2,995,269		2,995,269		2,223,220
2021	2,070,434		2,070,434		1,459,559
2020	1,407,929		1,407,929		921,574
Prior	3,503,099		3,503,099		2,846,088
Revolving Loans	1,798,809		1,798,809		1,674,790
Revolving Loans Converted to Term Loans	23,071		23,071		20,878
Total	14,109,919		14,109,919		13,948,360
Current period gross charge-offs
Total	1,692	$ 845	9,707	$ 1,756
Commercial and industrial | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	184,389		184,389		482,901
2023	430,433		430,433		480,687
2022	410,348		410,348		367,551
2021	333,808		333,808		355,211
2020	341,110		341,110		140,730
Prior	751,710		751,710		644,484
Revolving Loans	618,169		618,169		544,357
Revolving Loans Converted to Term Loans	1,240		1,240		3,710
Total	3,071,207		3,071,207		3,019,631
Current period gross charge-offs
2024			0
2023			0
2022			0
2021			0
2020			0
Prior			0
Revolving Loans			0
Revolving Loans Converted to Term Loans			0
Total	0	0	0	0
Commercial and industrial | Pass | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	173,503		173,503		477,138
2023	391,758		391,758		442,896
2022	369,396		369,396		350,782
2021	266,102		266,102		341,243
2020	326,612		326,612		140,641
Prior	744,362		744,362		641,342
Revolving Loans	559,005		559,005		485,448
Revolving Loans Converted to Term Loans	501		501		3,255
Total	2,831,239		2,831,239		2,882,745
Commercial and industrial | Special Mention | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	10,886		10,886		4,229
2023	20,156		20,156		25,796
2022	20,782		20,782		14,994
2021	67,706		67,706		13,563
2020	3,978		3,978		89
Prior	6,785		6,785		553
Revolving Loans	35,917		35,917		51,106
Revolving Loans Converted to Term Loans	303		303		455
Total	166,513		166,513		110,785
Commercial and industrial | Substandard | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		1,534
2023	18,519		18,519		11,995
2022	20,170		20,170		1,775
2021	0		0		405
2020	10,520		10,520		0
Prior	555		555		2,581
Revolving Loans	23,247		23,247		7,803
Revolving Loans Converted to Term Loans	436		436		0
Total	73,447		73,447		26,093
Commercial and industrial | Doubtful | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	8		8		8
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	8		8		8
Commercial and industrial | Loss | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	0		0		0
Commercial real estate | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	204,505		204,505		544,143
2023	560,367		560,367		1,456,472
2022	1,400,803		1,400,803		870,251
2021	859,674		859,674		578,044
2020	566,055		566,055		552,383
Prior	1,786,285		1,786,285		1,394,411
Revolving Loans	51,831		51,831		55,587
Revolving Loans Converted to Term Loans	7,878		7,878		2,556
Total	5,437,398		5,437,398		5,453,847
Current period gross charge-offs
2024			0
2023			0
2022			0
2021			0
2020			0
Prior			7,250
Revolving Loans			0
Revolving Loans Converted to Term Loans			0
Total	0	0	7,250	0
Commercial real estate | Pass | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	194,930		194,930		498,590
2023	474,588		474,588		1,435,893
2022	1,380,390		1,380,390		855,014
2021	804,934		804,934		573,370
2020	552,530		552,530		516,689
Prior	1,630,590		1,630,590		1,291,189
Revolving Loans	45,966		45,966		47,581
Revolving Loans Converted to Term Loans	0		0		2,556
Total	5,083,928		5,083,928		5,220,882
Commercial real estate | Special Mention | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	1,256		1,256		15,200
2023	45,208		45,208		7,990
2022	7,927		7,927		0
2021	48,067		48,067		736
2020	11,234		11,234		2,281
Prior	15,170		15,170		34,803
Revolving Loans	5,863		5,863		0
Revolving Loans Converted to Term Loans	0		0		0
Total	134,725		134,725		61,010
Commercial real estate | Substandard | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	8,319		8,319		19,738
2023	40,571		40,571		12,589
2022	12,486		12,486		15,237
2021	6,673		6,673		3,938
2020	2,291		2,291		33,413
Prior	117,267		117,267		48,978
Revolving Loans	2		2		8,006
Revolving Loans Converted to Term Loans	7,878		7,878		0
Total	195,487		195,487		141,899
Commercial real estate | Doubtful | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		10,615
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	23,258		23,258		19,441
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	23,258		23,258		30,056
Commercial real estate | Loss | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	0		0		0
Commercial construction | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	41,542		41,542		133,919
2023	188,150		188,150		151,957
2022	193,997		193,997		96,147
2021	21,538		21,538		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		2,614
Revolving Loans Converted to Term Loans	0		0		0
Total	445,227		445,227		384,637
Current period gross charge-offs
2024			0
2023			0
2022			0
2021			0
2020			0
Prior			0
Revolving Loans			0
Revolving Loans Converted to Term Loans			0
Total	0	0	0	0
Commercial construction | Pass | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	41,542		41,542		133,463
2023	164,646		164,646		151,957
2022	193,997		193,997		96,147
2021	21,538		21,538		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		2,614
Revolving Loans Converted to Term Loans	0		0		0
Total	421,723		421,723		384,181
Commercial construction | Special Mention | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		456
2023	485		485		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	485		485		456
Commercial construction | Substandard | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	23,019		23,019		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	23,019		23,019		0
Commercial construction | Doubtful | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	0		0		0
Commercial construction | Loss | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	0		0		0
Business banking | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	88,575		88,575		142,021
2023	129,725		129,725		168,396
2022	161,357		161,357		186,299
2021	176,562		176,562		152,545
2020	142,661		142,661		117,301
Prior	328,708		328,708		244,758
Revolving Loans	80,195		80,195		73,671
Revolving Loans Converted to Term Loans	3,160		3,160		4,602
Total	1,110,943		1,110,943		1,089,593
Current period gross charge-offs
2024			0
2023			405
2022			0
2021			418
2020			144
Prior			119
Revolving Loans			0
Revolving Loans Converted to Term Loans			18
Total	1,002	254	1,104	597
Business banking | Pass | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	87,499		87,499		139,237
2023	128,351		128,351		165,247
2022	158,460		158,460		182,606
2021	171,739		171,739		146,180
2020	137,208		137,208		110,638
Prior	314,233		314,233		229,636
Revolving Loans	79,495		79,495		73,054
Revolving Loans Converted to Term Loans	3,055		3,055		3,996
Total	1,080,040		1,080,040		1,050,594
Business banking | Special Mention | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	905		905		1,474
2023	224		224		2,553
2022	2,332		2,332		1,009
2021	2,364		2,364		4,294
2020	2,563		2,563		4,692
Prior	9,380		9,380		11,479
Revolving Loans	111		111		23
Revolving Loans Converted to Term Loans	41		41		27
Total	17,920		17,920		25,551
Business banking | Substandard | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	171		171		1,310
2023	1,150		1,150		596
2022	565		565		2,684
2021	2,459		2,459		2,071
2020	2,890		2,890		1,464
Prior	5,087		5,087		3,423
Revolving Loans	214		214		594
Revolving Loans Converted to Term Loans	64		64		579
Total	12,600		12,600		12,721
Business banking | Doubtful | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		507
Prior	8		8		220
Revolving Loans	375		375		0
Revolving Loans Converted to Term Loans	0		0		0
Total	383		383		727
Business banking | Loss | Commercial Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	0		0		0
Residential real estate | Residential Real Estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	86,079		86,079		258,421
2023	249,313		249,313		737,367
2022	718,042		718,042		669,681
2021	650,126		650,126		356,406
2020	343,412		343,412		95,601
Prior	530,793		530,793		464,989
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	2,577,765		2,577,765		2,582,465
Current period gross charge-offs
2024			0
2023			0
2022			0
2021			0
2020			0
Prior			10
Revolving Loans			0
Revolving Loans Converted to Term Loans			0
Total	0	0	10	0
Residential real estate | Residential Real Estate | Current and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	86,079		86,079		257,671
2023	248,027		248,027		728,997
2022	712,314		712,314		665,811
2021	644,880		644,880		354,003
2020	340,910		340,910		93,817
Prior	516,722		516,722		451,812
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	2,548,932		2,548,932		2,552,111
Residential real estate | Residential Real Estate | 30-89 days past due and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		750
2023	1,286		1,286		6,615
2022	3,388		3,388		2,437
2021	4,910		4,910		2,112
2020	2,502		2,502		1,496
Prior	9,958		9,958		8,219
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	22,044		22,044		21,629
Residential real estate | Residential Real Estate | Loans 90 days or more past due and still accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	0		0		0
Residential real estate | Residential Real Estate | Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		1,755
2022	2,340		2,340		1,433
2021	336		336		291
2020	0		0		288
Prior	4,113		4,113		4,958
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	6,789		6,789		8,725
Consumer home equity | Consumer Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	3,689		3,689		30,541
2023	27,211		27,211		84,614
2022	79,233		79,233		9,151
2021	8,263		8,263		4,899
2020	4,604		4,604		4,166
Prior	86,336		86,336		82,711
Revolving Loans	1,036,758		1,036,758		985,161
Revolving Loans Converted to Term Loans	10,716		10,716		9,925
Total	1,256,810		1,256,810		1,211,168
Current period gross charge-offs
2024			0
2023			0
2022			0
2021			0
2020			0
Prior			2
Revolving Loans			32
Revolving Loans Converted to Term Loans			0
Total	32	0	34	7
Consumer home equity | Consumer Portfolio Segment | Current and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	3,689		3,689		30,393
2023	27,147		27,147		84,065
2022	79,038		79,038		9,151
2021	8,263		8,263		4,899
2020	4,604		4,604		4,166
Prior	84,413		84,413		80,687
Revolving Loans	1,023,450		1,023,450		970,882
Revolving Loans Converted to Term Loans	10,413		10,413		9,472
Total	1,241,017		1,241,017		1,193,715
Consumer home equity | Consumer Portfolio Segment | 30-89 days past due and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		148
2023	64		64		483
2022	143		143		0
2021	0		0		0
2020	0		0		0
Prior	779		779		558
Revolving Loans	7,871		7,871		7,509
Revolving Loans Converted to Term Loans	221		221		223
Total	9,078		9,078		8,921
Consumer home equity | Consumer Portfolio Segment | Loans 90 days or more past due and still accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	0		0		0
Consumer home equity | Consumer Portfolio Segment | Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		66
2022	52		52		0
2021	0		0		0
2020	0		0		0
Prior	1,144		1,144		1,466
Revolving Loans	5,437		5,437		6,770
Revolving Loans Converted to Term Loans	82		82		230
Total	6,715		6,715		8,532
Other Consumer | Consumer Portfolio Segment
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	46,637		46,637		93,879
2023	70,693		70,693		36,933
2022	31,489		31,489		24,140
2021	20,463		20,463		12,454
2020	10,087		10,087		11,393
Prior	19,267		19,267		14,735
Revolving Loans	11,856		11,856		13,400
Revolving Loans Converted to Term Loans	77		77		85
Total	210,569		210,569		207,019
Current period gross charge-offs
2024			494
2023			183
2022			301
2021			183
2020			24
Prior			66
Revolving Loans			58
Revolving Loans Converted to Term Loans			0
Total	658	$ 591	1,309	$ 1,152
Other Consumer | Consumer Portfolio Segment | Current and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	46,608		46,608		93,659
2023	70,543		70,543		36,601
2022	31,372		31,372		23,962
2021	20,407		20,407		12,427
2020	10,046		10,046		11,367
Prior	19,196		19,196		14,609
Revolving Loans	11,759		11,759		13,353
Revolving Loans Converted to Term Loans	29		29		85
Total	209,960		209,960		206,063
Other Consumer | Consumer Portfolio Segment | 30-89 days past due and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	29		29		170
2023	96		96		271
2022	95		95		153
2021	49		49		25
2020	29		29		12
Prior	46		46		92
Revolving Loans	89		89		40
Revolving Loans Converted to Term Loans	48		48		0
Total	481		481		763
Other Consumer | Consumer Portfolio Segment | Loans 90 days or more past due and still accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		0
2023	0		0		0
2022	0		0		0
2021	0		0		0
2020	0		0		0
Prior	0		0		0
Revolving Loans	0		0		0
Revolving Loans Converted to Term Loans	0		0		0
Total	0		0		0
Other Consumer | Consumer Portfolio Segment | Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2024	0		0		50
2023	54		54		61
2022	22		22		25
2021	7		7		2
2020	12		12		14
Prior	25		25		34
Revolving Loans	8		8		7
Revolving Loans Converted to Term Loans	0		0		0
Total	$ 128		$ 128		$ 193