Loans - Residential, Home Equity and Consumer Loans Based on Payment Activity (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 5,858,642		$ 5,884,448
Current Period Gross Charge-Offs
Total	1,468	$ 625
Consumer Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	9,448		58,703
Year two	53,444		28,567
Year three	19,527		13,023
Year four	11,479		5,100
Year five	4,306		3,489
Prior	4,975		2,434
Revolving Loans Amortized Cost Basis	6,886		6,332
Total	110,065		117,648
Current Period Gross Charge-Offs
Year one	356		1,502
Year two	1		51
Year three	23		66
Year four	9		30
Year five	1		15
Prior	5		3
Revolving Loans Amortized Cost Basis	0		0
Total	395	325	1,667
Consumer Loans | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	9,448		58,703
Year two	53,439		28,540
Year three	19,263		13,023
Year four	11,464		5,094
Year five	4,306		3,489
Prior	4,973		2,434
Revolving Loans Amortized Cost Basis	6,886		6,332
Total	109,779		117,615
Consumer Loans | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	5		27
Year three	264		0
Year four	15		6
Year five	0		0
Prior	2		0
Revolving Loans Amortized Cost Basis	0		0
Total	286		33
Home Equity Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		315
Year two	379		1,706
Year three	1,685		1,693
Year four	2,005		4,151
Year five	4,223		1,379
Prior	5,998		4,758
Revolving Loans Amortized Cost Basis	486,406		470,298
Total	500,696		484,300
Current Period Gross Charge-Offs
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		68
Year five	0		25
Prior	0		3
Revolving Loans Amortized Cost Basis	0		0
Total	0	0	96
Home Equity Loans | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		315
Year two	379		1,706
Year three	1,508		1,495
Year four	1,799		3,900
Year five	4,064		1,294
Prior	5,788		4,672
Revolving Loans Amortized Cost Basis	486,382		470,142
Total	499,920		483,524
Home Equity Loans | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	0		0
Year three	177		198
Year four	206		251
Year five	159		85
Prior	210		86
Revolving Loans Amortized Cost Basis	24		156
Total	776		776
Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	9,699		78,420
Year two	81,094		84,022
Year three	83,536		99,206
Year four	94,311		188,642
Year five	185,299		142,534
Prior	313,950		181,729
Revolving Loans Amortized Cost Basis	0		0
Total	767,889		774,553
Current Period Gross Charge-Offs
Year one	0		0
Year two	0		0
Year three	0		77
Year four	51		0
Year five	0		37
Prior	59		0
Revolving Loans Amortized Cost Basis	0		0
Total	110	$ 0	114
Residential Mortgage Loans | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	9,699		78,420
Year two	81,094		83,687
Year three	83,204		99,058
Year four	93,848		188,414
Year five	184,548		142,032
Prior	311,865		180,555
Revolving Loans Amortized Cost Basis	0		0
Total	764,258		772,166
Residential Mortgage Loans | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	0		335
Year three	332		148
Year four	463		228
Year five	751		502
Prior	2,085		1,174
Revolving Loans Amortized Cost Basis	0		0
Total	$ 3,631		$ 2,387