Loan Portfolio and Allowance for Credit Losses - Risk Category Loans by Class of Loans (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Total loans	$ 316,763		$ 313,443
Current-period Gross writeoffs	19	$ 4
Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Total loans	4,962,798		4,927,461
Current-period Gross writeoffs	0	80
Installment [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	423		3,089
2026/2025	2,965		1,973
2025/2024	1,668		3,195
2024/2023	2,700		1,588
2023/2022	1,328		257
Prior	634		562
Revolving Loans Amortized Cost Basis	899		892
Revolving Loan Converted to Term	0		0
Total loans	10,617		11,556
2027/2026	0		9
2026/2025	4		102
2025/2024	1		17
2024/2023	18		20
2023/2022	2		27
Prior	1		42
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	26	$ 40	217
Commercial Real Estate [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	10,605		47,620
2026/2025	47,474		48,708
2025/2024	47,787		49,673
2024/2023	48,227		67,129
2023/2022	65,081		21,050
Prior	74,945		56,233
Revolving Loans Amortized Cost Basis	4,061		4,694
Revolving Loan Converted to Term	0		0
Total loans	298,180		295,107
2027/2026	0		0
2026/2025	0		0
2025/2024	0		0
2024/2023	0		0
2023/2022	19		4
Prior	0		0
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	19		4
Other [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	1,334		4,453
2026/2025	4,251		1,332
2025/2024	1,201		6,346
2024/2023	6,149		1,228
2023/2022	1,170		137
Prior	467		1,218
Revolving Loans Amortized Cost Basis	4,011		3,622
Revolving Loan Converted to Term	0		0
Total loans	18,583		18,336
2027/2026	0		0
2026/2025	0		0
2025/2024	0		0
2024/2023	0		0
2023/2022	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	0		0
First Mortgages [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	110,099		382,926
2026/2025	388,811		308,123
2025/2024	297,778		367,683
2024/2023	361,536		501,014
2023/2022	495,141		759,470
Prior	2,777,576		2,078,355
Revolving Loans Amortized Cost Basis	1,784		1,653
Revolving Loan Converted to Term	0		0
Total loans	4,432,725		4,399,224
2027/2026	0		0
2026/2025	0		0
2025/2024	0		0
2024/2023	0		0
2023/2022	0		0
Prior	0		99
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	0		99
Home Equity Loans [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	3,858		17,600
2026/2025	17,251		5,386
2025/2024	5,001		7,138
2024/2023	6,645		4,450
2023/2022	4,166		5,328
Prior	28,265		24,134
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	65,186		64,036
2027/2026	0		0
2026/2025	0		0
2025/2024	0		0
2024/2023	0		0
2023/2022	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	0		0
Home Equity Line of Credit [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	594		1,718
2026/2025	2,345		3,985
2025/2024	3,139		1,471
2024/2023	1,275		1,196
2023/2022	1,337		1,504
Prior	25,159		21,024
Revolving Loans Amortized Cost Basis	431,038		433,303
Revolving Loan Converted to Term	0		0
Total loans	464,887		464,201
2027/2026	0		0
2026/2025	0		0
2025/2024	0		0
2024/2023	0		0
2023/2022	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	0		0
Performing [Member] | Installment [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	423		3,089
2026/2025	2,942		1,973
2025/2024	1,668		3,191
2024/2023	2,700		1,542
2023/2022	1,290		257
Prior	633		561
Revolving Loans Amortized Cost Basis	898		892
Revolving Loan Converted to Term	0		0
Total loans	10,554		11,505
Performing [Member] | First Mortgages [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	110,099		382,926
2026/2025	388,811		307,952
2025/2024	297,056		366,470
2024/2023	359,822		499,812
2023/2022	493,884		757,834
Prior	2,764,516		2,066,631
Revolving Loans Amortized Cost Basis	1,784		1,653
Revolving Loan Converted to Term	0		0
Total loans	4,415,972		4,383,278
Performing [Member] | Home Equity Loans [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	3,858		17,600
2026/2025	17,251		5,386
2025/2024	5,001		7,138
2024/2023	6,645		4,384
2023/2022	4,100		5,328
Prior	27,921		23,770
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	64,776		63,606
Performing [Member] | Home Equity Line of Credit [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	594		1,718
2026/2025	2,345		3,985
2025/2024	3,045		1,471
2024/2023	1,146		1,196
2023/2022	1,337		1,504
Prior	23,383		19,145
Revolving Loans Amortized Cost Basis	430,766		432,926
Revolving Loan Converted to Term	0		0
Total loans	462,616		461,945
Nonperforming [Member] | Installment [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	0		0
2026/2025	23		0
2025/2024	0		4
2024/2023	0		46
2023/2022	38		0
Prior	1		1
Revolving Loans Amortized Cost Basis	1		0
Revolving Loan Converted to Term	0		0
Total loans	63		51
Nonperforming [Member] | First Mortgages [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	0		0
2026/2025	0		171
2025/2024	722		1,213
2024/2023	1,714		1,202
2023/2022	1,257		1,636
Prior	13,060		11,724
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	16,753		15,946
Nonperforming [Member] | Home Equity Loans [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	0		0
2026/2025	0		0
2025/2024	0		0
2024/2023	0		66
2023/2022	66		0
Prior	344		364
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	410		430
Nonperforming [Member] | Home Equity Line of Credit [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	0		0
2026/2025	0		0
2025/2024	94		0
2024/2023	129		0
2023/2022	0		0
Prior	1,776		1,879
Revolving Loans Amortized Cost Basis	272		377
Revolving Loan Converted to Term	0		0
Total loans	2,271		2,256
Pass [Member] | Commercial Real Estate [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	10,605		47,620
2026/2025	47,474		47,818
2025/2024	46,897		49,673
2024/2023	48,227		65,902
2023/2022	63,528		21,050
Prior	74,273		55,543
Revolving Loans Amortized Cost Basis	4,061		4,694
Revolving Loan Converted to Term	0		0
Total loans	295,065		292,300
Pass [Member] | Other [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	1,334		4,453
2026/2025	4,251		1,322
2025/2024	1,192		6,346
2024/2023	6,104		1,228
2023/2022	1,170		136
Prior	467		1,218
Revolving Loans Amortized Cost Basis	3,971		3,538
Revolving Loan Converted to Term	0		0
Total loans	18,489		18,241
Special Mention [Member] | Commercial Real Estate [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	0		0
2026/2025	0		0
2025/2024	0		0
2024/2023	0		237
2023/2022	584		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	584		237
Special Mention [Member] | Other [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	0		0
2026/2025	0		0
2025/2024	0		0
2024/2023	45		0
2023/2022	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		45
Revolving Loan Converted to Term	0		0
Total loans	45		45
Substandard [Member] | Commercial Real Estate [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	0		0
2026/2025	0		890
2025/2024	890		0
2024/2023	0		990
2023/2022	969		0
Prior	672		690
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	2,531		2,570
Substandard [Member] | Other [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	0		0
2026/2025	0		10
2025/2024	9		0
2024/2023	0		0
2023/2022	0		1
Prior	0		0
Revolving Loans Amortized Cost Basis	40		39
Revolving Loan Converted to Term	0		0
Total loans	49		50
Doubtful [Member] | Commercial Real Estate [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	0		0
2026/2025	0		0
2025/2024	0		0
2024/2023	0		0
2023/2022	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	0		0
Doubtful [Member] | Other [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
2027/2026	0		0
2026/2025	0		0
2025/2024	0		0
2024/2023	0		0
2023/2022	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	$ 0		$ 0