Loan Portfolio and Allowance for Credit Losses, Risk Category of Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Credit Risk Profile, Segregated by Class [Abstract]
Total loans	$ 5,070,856		$ 5,070,856		$ 5,002,879
Current-period Gross writeoffs	318	$ 50	513	$ 189
Commercial [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Total loans	280,261		280,261		273,515
Current-period Gross writeoffs	65	0	65	0
Commercial [Member] | Commercial Real Estate [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	34,827		34,827		61,148
2023/2022	54,126		54,126		82,339
2022/2021	76,436		76,436		23,940
2021/2020	22,445		22,445		16,695
2020/2019	15,451		15,451		19,835
Prior	53,477		53,477		42,634
Revolving Loans Amortized Cost Basis	2,801		2,801		5,664
Revolving Loan Converted to Term	0		0		0
Total loans	259,563		259,563		252,255
2024/2023			0		0
2023/2022			0		0
2022/2021			0		0
2021/2020			0		0
2020/2019			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
Commercial [Member] | Commercial Real Estate [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	34,827		34,827		61,148
2023/2022	54,126		54,126		82,339
2022/2021	75,176		75,176		23,940
2021/2020	22,445		22,445		16,653
2020/2019	15,425		15,425		19,835
Prior	52,536		52,536		41,153
Revolving Loans Amortized Cost Basis	2,801		2,801		5,664
Revolving Loan Converted to Term	0		0		0
Total loans	257,336		257,336		250,732
Commercial [Member] | Commercial Real Estate [Member] | Special Mention [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	0		0		0
2023/2022	0		0		0
2022/2021	1,070		1,070		0
2021/2020	0		0		42
2020/2019	26		26		0
Prior	524		524		225
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	1,620		1,620		267
Commercial [Member] | Commercial Real Estate [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	0		0		0
2023/2022	0		0		0
2022/2021	190		190		0
2021/2020	0		0		0
2020/2019	0		0		0
Prior	379		379		1,256
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	569		569		1,256
Commercial [Member] | Commercial Real Estate [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	0		0
2023/2022	0		0
2022/2021	0		0
2021/2020	0		0
2020/2019	0		0
Prior	38		38
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	38		38
Commercial [Member] | Other [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	1,587		1,587		7,873
2023/2022	7,627		7,627		2,164
2022/2021	1,890		1,890		2,261
2021/2020	963		963		1,386
2020/2019	265		265		321
Prior	1,880		1,880		2,739
Revolving Loans Amortized Cost Basis	6,486		6,486		4,516
Revolving Loan Converted to Term	0		0		0
Total loans	20,698		20,698		21,260
2024/2023			0		0
2023/2022			0		0
2022/2021			0		0
2021/2020			0		0
2020/2019			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
Commercial [Member] | Other [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	1,573		1,573		7,873
2023/2022	7,627		7,627		2,164
2022/2021	1,890		1,890		1,933
2021/2020	517		517		1,386
2020/2019	265		265		321
Prior	1,745		1,745		2,641
Revolving Loans Amortized Cost Basis	6,201		6,201		4,482
Revolving Loan Converted to Term	0		0		0
Total loans	19,818		19,818		20,800
Commercial [Member] | Other [Member] | Special Mention [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	14		14		0
2023/2022	0		0		0
2022/2021	0		0		0
2021/2020	0		0		0
2020/2019	0		0		0
Prior	37		37		0
Revolving Loans Amortized Cost Basis	0		0		34
Revolving Loan Converted to Term	0		0		0
Total loans	51		51		34
Commercial [Member] | Other [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	0		0		0
2023/2022	0		0		0
2022/2021	0		0		328
2021/2020	132		132		0
2020/2019	0		0		0
Prior	98		98		98
Revolving Loans Amortized Cost Basis	285		285		0
Revolving Loan Converted to Term	0		0		0
Total loans	515		515		426
Commercial [Member] | Other [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	0		0
2023/2022	0		0
2022/2021	0		0
2021/2020	314		314
2020/2019	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	314		314
Real Estate Mortgage - 1 to 4 Family [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Total loans	4,776,092		4,776,092		4,712,478
Current-period Gross writeoffs	194	27	328	49
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	227,310		227,310		418,955
2023/2022	409,727		409,727		566,827
2022/2021	543,812		543,812		878,398
2021/2020	836,381		836,381		733,080
2020/2019	694,534		694,534		343,678
Prior	1,613,390		1,613,390		1,366,167
Revolving Loans Amortized Cost Basis	710		710		0
Revolving Loan Converted to Term	0		0		0
Total loans	4,325,864		4,325,864		4,307,105
2024/2023			193		0
2023/2022			0		0
2022/2021			0		0
2021/2020			0		0
2020/2019			0		27
Prior			19		336
Revolving Loans Amortized Cost Basis Writeoffs			0		0
Revolving Loan Converted to Term Writeoffs			0		0
Current-period Gross writeoffs			212		363
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	227,310		227,310		418,891
2023/2022	409,174		409,174		566,617
2022/2021	543,602		543,602		878,015
2021/2020	835,847		835,847		732,851
2020/2019	694,291		694,291		342,559
Prior	1,600,046		1,600,046		1,354,867
Revolving Loans Amortized Cost Basis	710		710		0
Revolving Loan Converted to Term	0		0		0
Total loans	4,310,980		4,310,980		4,293,800
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	0		0		64
2023/2022	553		553		210
2022/2021	210		210		383
2021/2020	534		534		229
2020/2019	243		243		1,119
Prior	13,344		13,344		11,300
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	14,884		14,884		13,305
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	4,777		4,777		9,660
2023/2022	8,972		8,972		5,963
2022/2021	5,601		5,601		7,770
2021/2020	6,837		6,837		5,668
2020/2019	5,180		5,180		6,542
Prior	25,443		25,443		22,355
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	56,810		56,810		57,958
2024/2023			0		0
2023/2022			0		0
2022/2021			0		0
2021/2020			0		0
2020/2019			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
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	4,777		4,777		9,660
2023/2022	8,972		8,972		5,963
2022/2021	5,446		5,446		7,770
2021/2020	6,837		6,837		5,668
2020/2019	5,180		5,180		6,542
Prior	25,066		25,066		22,076
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	56,278		56,278		57,679
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	0		0		0
2023/2022	0		0		0
2022/2021	155		155		0
2021/2020	0		0		0
2020/2019	0		0		0
Prior	377		377		279
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	532		532		279
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	4,171		4,171		355
2023/2022	1,218		1,218		641
2022/2021	1,160		1,160		256
2021/2020	668		668		131
2020/2019	227		227		10
Prior	16,880		16,880		18,777
Revolving Loans Amortized Cost Basis	369,094		369,094		327,245
Revolving Loan Converted to Term	0		0		0
Total loans	393,418		393,418		347,415
2024/2023			0		0
2023/2022			0		0
2022/2021			0		0
2021/2020			0		0
2020/2019			0		0
Prior			116		8
Revolving Loans Amortized Cost Basis Writeoffs			0		0
Revolving Loan Converted to Term Writeoffs			0		0
Current-period Gross writeoffs			116		8
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	4,171		4,171		355
2023/2022	1,218		1,218		641
2022/2021	1,160		1,160		248
2021/2020	668		668		75
2020/2019	227		227		10
Prior	14,127		14,127		15,964
Revolving Loans Amortized Cost Basis	368,767		368,767		327,059
Revolving Loan Converted to Term	0		0		0
Total loans	390,338		390,338		344,352
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	0		0		0
2023/2022	0		0		0
2022/2021	0		0		8
2021/2020	0		0		56
2020/2019	0		0		0
Prior	2,753		2,753		2,813
Revolving Loans Amortized Cost Basis	327		327		186
Revolving Loan Converted to Term	0		0		0
Total loans	3,080		3,080		3,063
Installment [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	2,313		2,313		8,473
2023/2022	6,301		6,301		4,641
2022/2021	3,201		3,201		1,535
2021/2020	910		910		360
2020/2019	168		168		261
Prior	655		655		608
Revolving Loans Amortized Cost Basis	955		955		1,008
Revolving Loan Converted to Term	0		0		0
Total loans	14,503		14,503		16,886
2024/2023			0		16
2023/2022			54		67
2022/2021			44		50
2021/2020			0		1
2020/2019			4		21
Prior			18		21
Revolving Loans Amortized Cost Basis Writeoffs			0		0
Revolving Loan Converted to Term Writeoffs			0		0
Current-period Gross writeoffs	59	$ 23	120	$ 140	176
Installment [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	2,313		2,313		8,473
2023/2022	6,296		6,296		4,592
2022/2021	3,141		3,141		1,484
2021/2020	856		856		360
2020/2019	168		168		198
Prior	606		606		605
Revolving Loans Amortized Cost Basis	955		955		1,008
Revolving Loan Converted to Term	0		0		0
Total loans	14,335		14,335		16,720
Installment [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2024/2023	0		0		0
2023/2022	5		5		49
2022/2021	60		60		51
2021/2020	54		54		0
2020/2019	0		0		63
Prior	49		49		3
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	$ 168		$ 168		$ 166