Loans (Credit Quality Indicators Vintage) (Details) - USD ($) $ in Thousands		3 Months Ended			12 Months Ended
		Mar. 31, 2025		Mar. 31, 2024	Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	[1]	$ 5,096,210			$ 5,137,838
Gross charge-offs, current year		72			262
Gross charge-offs, prior year		0			10
Gross charge-offs, two years ago		0			0
Gross charge-offs, three years ago		0			0
Gross charge-offs, four years ago		0			2
Gross charge-offs, five years ago or more		2,450			2,139
Gross charge-offs, revolving loans		0			0
Gross charge-offs, revolving loans converted to term loans		0			0
Total gross charge-offs		2,522			2,413
Basis adjustment associated with fair value hedges		(699)			(1,481)
Financing Receivable
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		65,342			334,388
Term loans amortized cost, prior year		309,895			897,170
Term loans amortized cost, two years ago		906,122			1,502,297
Term loans amortized cost, three years ago		1,486,412			771,287
Term loans amortized cost, four years ago		742,460			342,333
Term loans amortized cost, five years ago or more		1,260,889			958,894
Revolving loans amortized cost		311,214			318,761
Revolving loans converted to term loans		14,575			14,189
Total loans		5,096,909			5,139,319
Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		25,074			203,941
Term loans amortized cost, prior year		182,997			438,879
Term loans amortized cost, two years ago		455,423			598,805
Term loans amortized cost, three years ago		593,928			362,292
Term loans amortized cost, four years ago		341,127			125,834
Term loans amortized cost, five years ago or more		523,076			413,885
Revolving loans amortized cost		11,505			9,879
Revolving loans converted to term loans		977			989
Total loans	[2]	2,134,107			2,154,504
Gross charge-offs, current year		0			0
Gross charge-offs, prior year		0			0
Gross charge-offs, two years ago		0			0
Gross charge-offs, three years ago		0			0
Gross charge-offs, four years ago		0			0
Gross charge-offs, five years ago or more		2,450			1,961
Gross charge-offs, revolving loans		0			0
Gross charge-offs, revolving loans converted to term loans		0			0
Total gross charge-offs		2,450		$ 0	1,961
Commercial real estate | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		25,074			172,931
Term loans amortized cost, prior year		153,946			432,763
Term loans amortized cost, two years ago		449,104			598,805
Term loans amortized cost, three years ago		588,539			362,292
Term loans amortized cost, four years ago		341,127			125,834
Term loans amortized cost, five years ago or more		514,620			405,381
Revolving loans amortized cost		11,505			9,879
Revolving loans converted to term loans		977			989
Total loans		2,084,892			2,108,874
Commercial real estate | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		0			0
Term loans amortized cost, prior year		0			6,116
Term loans amortized cost, two years ago		6,319			0
Term loans amortized cost, three years ago		5,389			0
Term loans amortized cost, four years ago		0			0
Term loans amortized cost, five years ago or more		2,217			2,237
Revolving loans amortized cost		0			0
Revolving loans converted to term loans		0			0
Total loans		13,925			8,353
Commercial real estate | Classified [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		0			31,010
Term loans amortized cost, prior year		29,051			0
Term loans amortized cost, two years ago		0			0
Term loans amortized cost, three years ago		0			0
Term loans amortized cost, four years ago		0			0
Term loans amortized cost, five years ago or more		6,239			6,267
Revolving loans amortized cost		0			0
Revolving loans converted to term loans		0			0
Total loans		35,290			37,277
Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		10,120			38,939
Term loans amortized cost, prior year		38,947			51,162
Term loans amortized cost, two years ago		50,522			140,042
Term loans amortized cost, three years ago		140,299			24,807
Term loans amortized cost, four years ago		23,764			38,352
Term loans amortized cost, five years ago or more		196,026			166,465
Revolving loans amortized cost		74,911			82,238
Revolving loans converted to term loans		441			469
Total loans	[3]	535,030			542,474
Gross charge-offs, current year		7			33
Gross charge-offs, prior year		0			0
Gross charge-offs, two years ago		0			0
Gross charge-offs, three years ago		0			0
Gross charge-offs, four years ago		0			0
Gross charge-offs, five years ago or more		0			175
Gross charge-offs, revolving loans		0			0
Gross charge-offs, revolving loans converted to term loans		0			0
Total gross charge-offs		7		8	208
Commercial & industrial | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		10,120			38,128
Term loans amortized cost, prior year		37,757			51,162
Term loans amortized cost, two years ago		50,099			136,449
Term loans amortized cost, three years ago		136,744			23,474
Term loans amortized cost, four years ago		22,345			36,954
Term loans amortized cost, five years ago or more		187,972			159,522
Revolving loans amortized cost		69,286			76,857
Revolving loans converted to term loans		441			469
Total loans		514,764			523,015
Commercial & industrial | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		0			0
Term loans amortized cost, prior year		808			0
Term loans amortized cost, two years ago		0			3,593
Term loans amortized cost, three years ago		3,555			1,172
Term loans amortized cost, four years ago		1,266			1,398
Term loans amortized cost, five years ago or more		7,720			6,428
Revolving loans amortized cost		5,625			5,381
Revolving loans converted to term loans		0			0
Total loans		18,974			17,972
Commercial & industrial | Classified [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		0			811
Term loans amortized cost, prior year		382			0
Term loans amortized cost, two years ago		423			0
Term loans amortized cost, three years ago		0			161
Term loans amortized cost, four years ago		153			0
Term loans amortized cost, five years ago or more		334			515
Revolving loans amortized cost		0			0
Revolving loans converted to term loans		0			0
Total loans		1,292			1,487
Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	[4]	2,113,307			2,126,171
Gross charge-offs, current year		0			0
Gross charge-offs, prior year		0			0
Gross charge-offs, two years ago		0			0
Gross charge-offs, three years ago		0			0
Gross charge-offs, four years ago		0			0
Gross charge-offs, five years ago or more		0			0
Gross charge-offs, revolving loans		0			0
Gross charge-offs, revolving loans converted to term loans		0			0
Total gross charge-offs		0		0	0
Residential real estate | Financing Receivable
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		25,464			74,458
Term loans amortized cost, prior year		72,611			384,270
Term loans amortized cost, two years ago		378,249			748,000
Term loans amortized cost, three years ago		737,570			375,848
Term loans amortized cost, four years ago		369,409			174,966
Term loans amortized cost, five years ago or more		530,703			370,110
Revolving loans amortized cost		0			0
Revolving loans converted to term loans		0			0
Total loans		2,114,006			2,127,652
Residential real estate | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		25,464			74,458
Term loans amortized cost, prior year		72,611			383,983
Term loans amortized cost, two years ago		377,854			746,566
Term loans amortized cost, three years ago		736,928			375,848
Term loans amortized cost, four years ago		369,409			173,676
Term loans amortized cost, five years ago or more		525,301	[5]		365,380
Revolving loans amortized cost		0			0
Revolving loans converted to term loans		0			0
Total loans		2,107,567	[5]		2,119,911
Residential real estate | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		0			0
Term loans amortized cost, prior year		0			287
Term loans amortized cost, two years ago		395			1,434
Term loans amortized cost, three years ago		642			0
Term loans amortized cost, four years ago		0			1,290
Term loans amortized cost, five years ago or more		5,402			4,730
Revolving loans amortized cost		0			0
Revolving loans converted to term loans		0			0
Total loans		6,439			7,741
Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		3,171			12,850
Term loans amortized cost, prior year		11,899			18,362
Term loans amortized cost, two years ago		17,847			12,749
Term loans amortized cost, three years ago		12,414			6,165
Term loans amortized cost, four years ago		6,035			2,424
Term loans amortized cost, five years ago or more		7,480			5,445
Revolving loans amortized cost		224,560			226,393
Revolving loans converted to term loans		13,157			12,731
Total loans		296,563			297,119
Gross charge-offs, current year		0			0
Gross charge-offs, prior year		0			0
Gross charge-offs, two years ago		0			0
Gross charge-offs, three years ago		0			0
Gross charge-offs, four years ago		0			0
Gross charge-offs, five years ago or more		0			0
Gross charge-offs, revolving loans		0			0
Gross charge-offs, revolving loans converted to term loans		0			0
Total gross charge-offs		0		0	0
Home equity | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		3,171			12,850
Term loans amortized cost, prior year		11,899			18,301
Term loans amortized cost, two years ago		17,754			12,749
Term loans amortized cost, three years ago		12,414			6,165
Term loans amortized cost, four years ago		6,035			2,282
Term loans amortized cost, five years ago or more		6,909			4,815
Revolving loans amortized cost		223,891			225,522
Revolving loans converted to term loans		11,912			11,488
Total loans		293,985			294,172
Home equity | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		0			0
Term loans amortized cost, prior year		0			61
Term loans amortized cost, two years ago		93			0
Term loans amortized cost, three years ago		0			0
Term loans amortized cost, four years ago		0			142
Term loans amortized cost, five years ago or more		571			630
Revolving loans amortized cost		669			871
Revolving loans converted to term loans		1,245			1,243
Total loans		2,578			2,947
Other
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		1,513			4,200
Term loans amortized cost, prior year		3,441			4,497
Term loans amortized cost, two years ago		4,081			2,701
Term loans amortized cost, three years ago		2,201			2,175
Term loans amortized cost, four years ago		2,125			757
Term loans amortized cost, five years ago or more		3,604			2,989
Revolving loans amortized cost		238			251
Revolving loans converted to term loans		0			0
Total loans	[6]	17,203			17,570
Gross charge-offs, current year		65			229
Gross charge-offs, prior year		0			10
Gross charge-offs, two years ago		0			0
Gross charge-offs, three years ago		0			0
Gross charge-offs, four years ago		0			2
Gross charge-offs, five years ago or more		0			3
Gross charge-offs, revolving loans		0			0
Gross charge-offs, revolving loans converted to term loans		0			0
Total gross charge-offs		65		$ 62	244
Other | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		1,482			4,176
Term loans amortized cost, prior year		3,441			4,497
Term loans amortized cost, two years ago		4,081			2,331
Term loans amortized cost, three years ago		2,201			2,175
Term loans amortized cost, four years ago		2,125			757
Term loans amortized cost, five years ago or more		3,604			2,989
Revolving loans amortized cost		237			251
Revolving loans converted to term loans		0			0
Total loans		17,171			17,176
Other | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost, current year		31			24
Term loans amortized cost, prior year		0			0
Term loans amortized cost, two years ago		0			370
Term loans amortized cost, three years ago		0			0
Term loans amortized cost, four years ago		0			0
Term loans amortized cost, five years ago or more		0			0
Revolving loans amortized cost		1			0
Revolving loans converted to term loans		0			0
Total loans		$ 32			$ 394

[1] Includes net unamortized loan origination costs of $11.3 million and $10.9 million, respectively, at March 31, 2025 and December 31, 2024 and net unamortized premiums on loans purchased from and serviced by other financial institutions of $233 thousand and $242 thousand, respectively, at March 31, 2025 and December 31, 2024.

[2] CRE consists of commercial mortgages primarily secured by non-owner occupied income-producing property, as well as construction and development loans. Construction and development loans are made to businesses for land development or the on-site construction of industrial, commercial, or residential buildings.

[3] C&I consists of loans to businesses and individuals, a portion of which are fully or partially collateralized by owner occupied real estate.

[4] Residential real estate consists of mortgage and homeowner construction loans secured by one- to four-family residential properties. Also, includes negative basis adjustments associated with fair value hedges of $699 thousand and $1.5 million, respectively, at March 31, 2025 and December 31, 2024. See Note 7 for additional disclosure.

[5] Excludes a $699 thousand negative basis adjustment associated with fair value hedges. See Note 7 for additional disclosure.

[6] Other consists of loans to individuals secured by general aviation aircraft and other personal installment loans.