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, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Credit Risk Profile, Segregated by Class [Abstract]
Total loans	$ 4,960,281		$ 4,960,281		$ 4,733,201
Current-period Gross writeoffs	50	$ 47	189	$ 118
Commercial [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Total loans	268,642		268,642		231,011
Current-period Gross writeoffs	0	0	0	40
Commercial [Member] | Commercial Real Estate [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	51,541		51,541		79,430
2022/2021	83,437		83,437		29,991
2021/2020	24,249		24,249		18,883
2020/2019	17,081		17,081		22,790
2019/2018	20,322		20,322		16,969
Prior	44,233		44,233		33,837
Revolving Loans Amortized Cost Basis	6,464		6,464		8,022
Revolving Loan Converted to Term	0		0		0
Total loans	247,327		247,327		209,922
2023/2022			0		0
2022/2021			0		0
2021/2020			0		0
2020/2019			0		0
2019/2018			0		0
Prior			0		40
Revolving Loans Amortized Cost Basis Writeoffs			0		0
Revolving Loan Converted to Term Writeoffs			0		0
Current-period Gross writeoffs			0		40
Commercial [Member] | Commercial Real Estate [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	51,541		51,541		79,430
2022/2021	83,437		83,437		29,991
2021/2020	24,249		24,249		18,708
2020/2019	16,926		16,926		22,790
2019/2018	20,322		20,322		16,598
Prior	42,634		42,634		32,666
Revolving Loans Amortized Cost Basis	6,464		6,464		8,022
Revolving Loan Converted to Term	0		0		0
Total loans	245,573		245,573		208,205
Commercial [Member] | Commercial Real Estate [Member] | Special Mention [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	0		0		0
2022/2021	0		0		0
2021/2020	0		0		62
2020/2019	47		47		0
2019/2018	0		0		243
Prior	230		230		0
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	277		277		305
Commercial [Member] | Commercial Real Estate [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	0		0		0
2022/2021	0		0		0
2021/2020	0		0		113
2020/2019	108		108		0
2019/2018	0		0		128
Prior	1,369		1,369		1,171
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	1,477		1,477		1,412
Commercial [Member] | Other [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	6,052		6,052		2,972
2022/2021	2,968		2,968		3,187
2021/2020	2,407		2,407		2,273
2020/2019	1,569		1,569		590
2019/2018	430		430		674
Prior	2,634		2,634		2,446
Revolving Loans Amortized Cost Basis	5,255		5,255		8,947
Revolving Loan Converted to Term	0		0		0
Total loans	21,315		21,315		21,089
2023/2022			0		0
2022/2021			0		0
2021/2020			0		0
2020/2019			0		0
2019/2018			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]
2023/2022	6,052		6,052		2,972
2022/2021	2,968		2,968		2,848
2021/2020	2,077		2,077		2,273
2020/2019	1,569		1,569		590
2019/2018	430		430		674
Prior	2,536		2,536		2,348
Revolving Loans Amortized Cost Basis	5,255		5,255		8,908
Revolving Loan Converted to Term	0		0		0
Total loans	20,887		20,887		20,613
Commercial [Member] | Other [Member] | Special Mention [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	0		0		0
2022/2021	0		0		0
2021/2020	0		0		0
2020/2019	0		0		0
2019/2018	0		0		0
Prior	0		0		0
Revolving Loans Amortized Cost Basis	0		0		39
Revolving Loan Converted to Term	0		0		0
Total loans	0		0		39
Commercial [Member] | Other [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	0		0		0
2022/2021	0		0		339
2021/2020	330		330		0
2020/2019	0		0		0
2019/2018	0		0		0
Prior	98		98		98
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	428		428		437
Real Estate Mortgage - 1 to 4 Family [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Total loans	4,675,034		4,675,034		4,489,883
Current-period Gross writeoffs	27	13	49	25
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	332,273		332,273		557,981
2022/2021	571,274		571,274		934,250
2021/2020	890,482		890,482		784,592
2020/2019	744,777		744,777		368,981
2019/2018	350,358		350,358		258,277
Prior	1,392,847		1,392,847		1,241,349
Revolving Loans Amortized Cost Basis	2,818		2,818		1,472
Revolving Loan Converted to Term	0		0		0
Total loans	4,284,829		4,284,829		4,146,902
2023/2022			0		0
2022/2021			0		0
2021/2020			0		0
2020/2019			0		0
2019/2018			27		0
Prior			22		5
Revolving Loans Amortized Cost Basis Writeoffs			0		0
Revolving Loan Converted to Term Writeoffs			0		0
Current-period Gross writeoffs			49		5
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	332,209		332,209		557,981
2022/2021	571,064		571,064		933,754
2021/2020	890,093		890,093		784,511
2020/2019	744,547		744,547		368,137
2019/2018	349,235		349,235		257,926
Prior	1,380,747		1,380,747		1,228,776
Revolving Loans Amortized Cost Basis	2,818		2,818		1,472
Revolving Loan Converted to Term	0		0		0
Total loans	4,270,713		4,270,713		4,132,557
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	64		64		0
2022/2021	210		210		496
2021/2020	389		389		81
2020/2019	230		230		844
2019/2018	1,123		1,123		351
Prior	12,100		12,100		12,573
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	14,116		14,116		14,345
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	8,095		8,095		6,863
2022/2021	6,112		6,112		9,124
2021/2020	8,136		8,136		6,322
2020/2019	5,757		5,757		7,588
2019/2018	6,667		6,667		5,306
Prior	23,410		23,410		21,346
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	58,177		58,177		56,549
2023/2022			0		0
2022/2021			0		0
2021/2020			0		0
2020/2019			0		0
2019/2018			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]
2023/2022	8,095		8,095		6,863
2022/2021	6,112		6,112		9,124
2021/2020	8,136		8,136		6,322
2020/2019	5,757		5,757		7,588
2019/2018	6,667		6,667		5,240
Prior	23,127		23,127		21,217
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	57,894		57,894		56,354
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	0		0		0
2022/2021	0		0		0
2021/2020	0		0		0
2020/2019	0		0		0
2019/2018	0		0		66
Prior	283		283		129
Revolving Loans Amortized Cost Basis	0		0		0
Revolving Loan Converted to Term	0		0		0
Total loans	283		283		195
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	766		766		1,369
2022/2021	824		824		1,253
2021/2020	365		365		740
2020/2019	126		126		52
2019/2018	30		30		100
Prior	18,861		18,861		20,488
Revolving Loans Amortized Cost Basis	311,056		311,056		262,430
Revolving Loan Converted to Term	0		0		0
Total loans	332,028		332,028		286,432
2023/2022			0		0
2022/2021			0		0
2021/2020			0		0
2020/2019			0		0
2019/2018			0		0
Prior			0		19
Revolving Loans Amortized Cost Basis Writeoffs			0		0
Revolving Loan Converted to Term Writeoffs			0		0
Current-period Gross writeoffs			0		19
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	766		766		1,369
2022/2021	824		824		1,246
2021/2020	365		365		740
2020/2019	126		126		52
2019/2018	30		30		100
Prior	16,765		16,765		18,377
Revolving Loans Amortized Cost Basis	310,690		310,690		262,244
Revolving Loan Converted to Term	0		0		0
Total loans	329,566		329,566		284,128
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	0		0		0
2022/2021	0		0		7
2021/2020	0		0		0
2020/2019	0		0		0
2019/2018	0		0		0
Prior	2,096		2,096		2,111
Revolving Loans Amortized Cost Basis	366		366		186
Revolving Loan Converted to Term	0		0		0
Total loans	2,462		2,462		2,304
Installment [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	7,330		7,330		6,405
2022/2021	5,169		5,169		2,512
2021/2020	1,718		1,718		805
2020/2019	452		452		774
2019/2018	345		345		374
Prior	596		596		309
Revolving Loans Amortized Cost Basis	995		995		1,128
Revolving Loan Converted to Term	0		0		0
Total loans	16,605		16,605		12,307
2023/2022			0		1
2022/2021			58		47
2021/2020			49		22
2020/2019			6		7
2019/2018			10		2
Prior			17		9
Revolving Loans Amortized Cost Basis Writeoffs			0		0
Revolving Loan Converted to Term Writeoffs			0		0
Current-period Gross writeoffs	23	$ 34	140	$ 53	88
Installment [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	7,330		7,330		6,385
2022/2021	5,137		5,137		2,495
2021/2020	1,667		1,667		805
2020/2019	452		452		709
2019/2018	277		277		374
Prior	594		594		308
Revolving Loans Amortized Cost Basis	990		990		1,125
Revolving Loan Converted to Term	0		0		0
Total loans	16,447		16,447		12,201
Installment [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2023/2022	0		0		20
2022/2021	32		32		17
2021/2020	51		51		0
2020/2019	0		0		65
2019/2018	68		68		0
Prior	2		2		1
Revolving Loans Amortized Cost Basis	5		5		3
Revolving Loan Converted to Term	0		0		0
Total loans	$ 158		$ 158		$ 106