Loans Receivable and Allowance for Credit Losses (Summary of Recorded Investment by Internal Risk Rating Systems) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 1,621,680,000	$ 1,603,877,000
Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024	28,930,000	134,225,000
2023	129,958,000	194,063,000
2022	192,963,000	146,073,000
2021	150,323,000	94,987,000
2020	92,181,000	93,173,000
Prior	324,164,000	239,295,000
Revolving Loans Amortized Cost Basis	70,990,000	69,741,000
Total	989,509,000	971,557,000
Pass [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024	28,930,000	132,372,000
2023	128,129,000	191,606,000
2022	185,073,000	145,229,000
2021	146,273,000	90,219,000
2020	89,083,000	92,513,000
Prior	314,215,000	229,990,000
Revolving Loans Amortized Cost Basis	65,579,000	63,589,000
Total	957,282,000	945,518,000
Special Mention [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024		1,853,000
2023	1,829,000	1,823,000
2022	1,976,000	502,000
2021	299,000	1,650,000
2020	1,431,000	505,000
Prior	7,221,000	6,835,000
Revolving Loans Amortized Cost Basis	3,496,000	2,652,000
Total	16,252,000	15,820,000
Substandard [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2023		634,000
2022	5,914,000	342,000
2021	3,751,000	3,118,000
2020	1,667,000	155,000
Prior	2,728,000	2,470,000
Revolving Loans Amortized Cost Basis	1,915,000	3,500,000
Total	15,975,000	10,219,000
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	691,755,000	675,156,000
Commercial Real Estate Loans [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024	11,173,000	79,796,000
2023	81,540,000	132,359,000
2022	134,179,000	112,345,000
2021	117,333,000	68,724,000
2020	68,968,000	72,516,000
Prior	262,176,000	194,505,000
Revolving Loans Amortized Cost Basis	16,386,000	14,911,000
Total	691,755,000	675,156,000
Current period gross charge-offs, 2020		112,000
Current period gross charge-offs, Prior		42,000
Current period gross charge-offs, Total		154,000
Commercial Real Estate Loans [Member] | Pass [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024	11,173,000	78,496,000
2023	80,240,000	131,948,000
2022	130,611,000	112,102,000
2021	114,116,000	65,949,000
2020	66,212,000	72,480,000
Prior	253,363,000	186,116,000
Revolving Loans Amortized Cost Basis	13,664,000	13,332,000
Total	669,379,000	660,423,000
Commercial Real Estate Loans [Member] | Special Mention [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024		1,300,000
2023	1,300,000	411,000
2022	624,000	243,000
2021	76,000	1,331,000
2020	1,321,000
Prior	6,134,000	6,157,000
Revolving Loans Amortized Cost Basis	2,722,000	1,579,000
Total	12,177,000	11,021,000
Commercial Real Estate Loans [Member] | Substandard [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2022	2,944,000
2021	3,141,000	1,444,000
2020	1,435,000	36,000
Prior	2,679,000	2,232,000
Total	10,199,000	3,712,000
Agricultural Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	62,309,000	63,859,000
Agricultural Real Estate Loans [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024	1,154,000	2,635,000
2023	2,628,000	13,017,000
2022	12,369,000	5,433,000
2021	5,391,000	8,624,000
2020	7,502,000	8,145,000
Prior	32,600,000	25,333,000
Revolving Loans Amortized Cost Basis	665,000	672,000
Total	62,309,000	63,859,000
Agricultural Real Estate Loans [Member] | Pass [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024	1,154,000	2,635,000
2023	2,628,000	12,509,000
2022	12,369,000	5,433,000
2021	5,391,000	7,606,000
2020	7,502,000	7,746,000
Prior	31,805,000	24,654,000
Revolving Loans Amortized Cost Basis	515,000	522,000
Total	61,364,000	61,105,000
Agricultural Real Estate Loans [Member] | Special Mention [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020		399,000
Prior	795,000	490,000
Revolving Loans Amortized Cost Basis	150,000	150,000
Total	945,000	1,039,000
Agricultural Real Estate Loans [Member] | Substandard [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2023		508,000
2021		1,018,000
Prior		189,000
Total		1,715,000
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	204,006,000	200,576,000
Commercial Loans [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024	16,042,000	49,124,000
2023	43,198,000	43,401,000
2022	41,598,000	25,042,000
2021	24,523,000	14,542,000
2020	12,748,000	9,934,000
Prior	23,790,000	15,621,000
Revolving Loans Amortized Cost Basis	42,107,000	42,912,000
Total	204,006,000	200,576,000
Current period gross charge-offs, 2023		32,000
Current period gross charge-offs, 2022		24,000
Current period gross charge-offs, 2021		4,856,000
Current period gross charge-offs, 2020	4,000
Current period gross charge-offs, Prior	51,000	41,000
Current period gross charge-offs, Total	55,000	4,953,000
Commercial Loans [Member] | Pass [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024	16,042,000	48,571,000
2023	42,669,000	41,863,000
2022	37,276,000	24,443,000
2021	23,691,000	13,752,000
2020	12,591,000	9,914,000
Prior	23,602,000	15,384,000
Revolving Loans Amortized Cost Basis	39,648,000	38,644,000
Total	195,519,000	192,571,000
Commercial Loans [Member] | Special Mention [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024		553,000
2023	529,000	1,412,000
2022	1,352,000	257,000
2021	222,000	134,000
2020	110,000	20,000
Prior	139,000	188,000
Revolving Loans Amortized Cost Basis	544,000	768,000
Total	2,896,000	3,332,000
Commercial Loans [Member] | Substandard [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2023		126,000
2022	2,970,000	342,000
2021	610,000	656,000
2020	47,000
Prior	49,000	49,000
Revolving Loans Amortized Cost Basis	1,915,000	3,500,000
Total	5,591,000	4,673,000
Other Agricultural Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	31,439,000	31,966,000
Other Agricultural Loans [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024	561,000	2,670,000
2023	2,592,000	5,286,000
2022	4,817,000	3,253,000
2021	3,076,000	3,097,000
2020	2,963,000	2,578,000
Prior	5,598,000	3,836,000
Revolving Loans Amortized Cost Basis	11,832,000	11,246,000
Total	31,439,000	31,966,000
Other Agricultural Loans [Member] | Pass [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2024	561,000	2,670,000
2023	2,592,000	5,286,000
2022	4,817,000	3,251,000
2021	3,075,000	2,912,000
2020	2,778,000	2,373,000
Prior	5,445,000	3,836,000
Revolving Loans Amortized Cost Basis	11,752,000	11,091,000
Total	31,020,000	31,419,000
Other Agricultural Loans [Member] | Special Mention [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2022		2,000
2021	1,000	185,000
2020		86,000
Prior	153,000
Revolving Loans Amortized Cost Basis	80,000	155,000
Total	234,000	428,000
Other Agricultural Loans [Member] | Substandard [Member] | Non-Homogenous Pools [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	185,000	119,000
Total	$ 185,000	$ 119,000