Retirement Benefit Plans (Details)	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Interest credit under cash balance plan	0.030
Employer matching contribution, percent of match, maximum	5.00%
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	$ 57,051,000	$ 57,051,000		$ 59,837,000	$ 57,051,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	57,051,000
Fair Value of Plan Assets, End of Period	59,837,000	57,051,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	$ 57,051,000	$ 57,051,000		$ 59,837,000	$ 57,051,000
Percent of Total				100.00%	100.00%
Expected Future Benefit Payments
Health Care Cost Trend   Rate Assumed for Next Year				7.00%	6.75%
Rate to which the Cost Trend   Rate is Assumed to Decline   (the Ultimate Trend Rate)				3.78%	3.78%
Year that the Rate Reaches    the Ultimate Trend Rate	2075	2075
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	$ 57,051,000	$ 57,051,000		$ 59,837,000	$ 57,051,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	57,051,000
Fair Value of Plan Assets, End of Period	59,837,000	57,051,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	57,051,000	57,051,000		59,837,000	57,051,000
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Cash
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		$ 0	$ 0
Percent of Total				0.00%	0.00%
Cash | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		$ 0	$ 0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Cash | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Cash | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Interest-Bearing Money Market Fund
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	2,742,000	2,742,000		1,124,000	2,742,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	2,742,000
Fair Value of Plan Assets, End of Period	1,124,000	2,742,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	2,742,000	2,742,000		$ 1,124,000	$ 2,742,000
Percent of Total				1.90%	4.80%
Interest-Bearing Money Market Fund | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	2,742,000	2,742,000		$ 1,124,000	$ 2,742,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	2,742,000
Fair Value of Plan Assets, End of Period	1,124,000	2,742,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	2,742,000	2,742,000		1,124,000	2,742,000
Interest-Bearing Money Market Fund | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Interest-Bearing Money Market Fund | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Common Stock
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	6,542,000	6,542,000		5,332,000	6,542,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	6,542,000
Fair Value of Plan Assets, End of Period	5,332,000	6,542,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	6,542,000	6,542,000		$ 5,332,000	$ 6,542,000
Percent of Total				8.90%	11.50%
Common Stock | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	6,542,000	6,542,000		$ 5,332,000	$ 6,542,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	6,542,000
Fair Value of Plan Assets, End of Period	5,332,000	6,542,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	6,542,000	6,542,000		5,332,000	6,542,000
Common Stock | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Common Stock | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
North Country Funds - Equity
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	21,209,000	21,209,000		25,741,000	21,209,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	21,209,000
Fair Value of Plan Assets, End of Period	25,741,000	21,209,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	21,209,000	21,209,000		$ 25,741,000	$ 21,209,000
Percent of Total				43.00%	37.20%
North Country Funds - Equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	21,209,000	21,209,000		$ 25,741,000	$ 21,209,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	21,209,000
Fair Value of Plan Assets, End of Period	25,741,000	21,209,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	21,209,000	21,209,000		25,741,000	21,209,000
North Country Funds - Equity | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
North Country Funds - Equity | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Other Mutual Funds - Equity
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	15,868,000	15,868,000		17,336,000	15,868,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	15,868,000
Fair Value of Plan Assets, End of Period	17,336,000	15,868,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	15,868,000	15,868,000		$ 17,336,000	$ 15,868,000
Percent of Total				29.00%	27.80%
Other Mutual Funds - Equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	15,868,000	15,868,000		$ 17,336,000	$ 15,868,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	15,868,000
Fair Value of Plan Assets, End of Period	17,336,000	15,868,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	15,868,000	15,868,000		17,336,000	15,868,000
Other Mutual Funds - Equity | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Other Mutual Funds - Equity | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Equity Funds
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	37,077,000	37,077,000		43,077,000	37,077,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	37,077,000
Fair Value of Plan Assets, End of Period	43,077,000	37,077,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	37,077,000	37,077,000		$ 43,077,000	$ 37,077,000
Percent of Total				72.00%	65.00%
Equity Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	37,077,000	37,077,000		$ 43,077,000	$ 37,077,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	37,077,000
Fair Value of Plan Assets, End of Period	43,077,000	37,077,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	37,077,000	37,077,000		43,077,000	37,077,000
Equity Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Equity Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
North Country Funds - Fixed Income
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	8,692,000	8,692,000		8,534,000	8,692,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	8,692,000
Fair Value of Plan Assets, End of Period	8,534,000	8,692,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	8,692,000	8,692,000		$ 8,534,000	$ 8,692,000
Percent of Total				14.30%	15.20%
North Country Funds - Fixed Income | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	8,692,000	8,692,000		$ 8,534,000	$ 8,692,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	8,692,000
Fair Value of Plan Assets, End of Period	8,534,000	8,692,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	8,692,000	8,692,000		8,534,000	8,692,000
North Country Funds - Fixed Income | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
North Country Funds - Fixed Income | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Other Mutual Funds - Fixed Income
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	793,000	793,000		805,000	793,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	793,000
Fair Value of Plan Assets, End of Period	805,000	793,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	793,000	793,000		$ 805,000	$ 793,000
Percent of Total				1.30%	1.40%
Other Mutual Funds - Fixed Income | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	793,000	793,000		$ 805,000	$ 793,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	793,000
Fair Value of Plan Assets, End of Period	805,000	793,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	793,000	793,000		805,000	793,000
Other Mutual Funds - Fixed Income | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Other Mutual Funds - Fixed Income | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Fixed Income Funds
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	9,485,000	9,485,000		9,339,000	9,485,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	9,485,000
Fair Value of Plan Assets, End of Period	9,339,000	9,485,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	9,485,000	9,485,000		$ 9,339,000	$ 9,485,000
Percent of Total				15.60%	16.60%
Fixed Income Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	9,485,000	9,485,000		$ 9,339,000	$ 9,485,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	9,485,000
Fair Value of Plan Assets, End of Period	9,339,000	9,485,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	9,485,000	9,485,000		9,339,000	9,485,000
Fixed Income Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Fixed Income Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Alternative ETF
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	1,205,000	1,205,000		965,000	1,205,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	1,205,000
Fair Value of Plan Assets, End of Period	965,000	1,205,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	1,205,000	1,205,000		$ 965,000	$ 1,205,000
Percent of Total				1.60%	2.10%
Alternative ETF | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	1,205,000	1,205,000		$ 965,000	$ 1,205,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	1,205,000
Fair Value of Plan Assets, End of Period	965,000	1,205,000
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	1,205,000	1,205,000		965,000	1,205,000
Alternative ETF | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	0	0		0	0
Alternative ETF | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0		0	0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0
Fair Value of Plan Assets, End of Period	0	0
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Fair Value of Plan Assets	$ 0	0		$ 0	0
Employees' Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Assumptions used calculating benefit obligation, interest rate to annuitize cash balance account				0.53%
Defined benefit plan, increase in benefit payable, percent				3.00%
Defined benefit plan, amortization of service cost	9 years 8 months 12 days
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	$ 57,051,000	57,051,000	$ 48,445,000	$ 59,837,000	57,051,000
Benefit Obligation	42,322,000	42,322,000	38,069,000	44,877,000	42,322,000
Funded Status of Plan				14,960,000	14,729,000
Change in Benefit Obligation
Benefit Obligation, Beginning of Period	42,322,000	38,069,000
Service Cost	1,663,000	1,527,000	1,557,000
Interest Cost	1,544,000	1,765,000	1,598,000
Plan Participants' Contributions	0	0
Amendments	351,638
Actuarial Loss	2,901,000	2,960,000
Benefits Paid	(3,905,000)	(1,999,000)
Benefit Obligation, End of Period	44,877,000	42,322,000	38,069,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	57,051,000	48,445,000
Actual Return on Plan Assets	6,691,000	10,605,000
Employer Contributions	0	0
Plan Participants' Contributions	0	0
Benefits Paid	(3,905,000)	(1,999,000)
Fair Value of Plan Assets, End of Period	59,837,000	57,051,000	48,445,000
Accumulated Benefit Obligation at December 31, 2020				44,613,000
Amounts Recognized in the Consolidated Balance Sheets
Prepaid Pension Asset				14,960,000	14,729,000
Accrued Benefit Liability				0	0
Net Benefit Recognized				14,960,000	14,729,000
Amounts Recognized in Other Comprehensive Income (Loss)
Net Unamortized (Gain) Loss Arising During the Period	(182,000)	(4,584,000)	4,480,000
Net Prior Service Cost Arising During the Period	349,000		0
Amortization of Net (Loss) Gain	(81,000)	(613,000)	(194,000)
Amortization of Prior Service Credit	(63,000)	(69,000)	49,000
Total Other Comprehensive Income for Pension and Other Postretirement Benefit Plans	23,000	(5,266,000)	4,335,000
Accumulated Other Comprehensive Income
Net Actuarial Loss (Gains)				5,482,000	5,745,000
Prior Service Cost				533,000	244,000
Total Accumulated Other Comprehensive Income, Before Tax				6,015,000	$ 5,989,000
Amounts that will be Amortized from Accumulated Other Comprehensive Income the Next Year
Net Actuarial Loss				0
Prior Service Cost				$ 78,000
Net Periodic Benefit Cost
Service Cost	1,663,000	1,527,000	1,557,000
Interest Cost	1,544,000	1,765,000	1,598,000
Expected Return on Plan Assets	(3,608,000)	(3,060,000)	(3,362,000)
Amortization of Prior Service (Credit) Cost	63,000	69,000	(49,000)
Amortization of Net Loss	81,000	613,000	194,000
Net Periodic Benefit Cost	$ (257,000)	$ 914,000	$ (62,000)
Weighted-Average Assumptions Used in Calculating Benefit Obligation
Discount Rate				3.14%	3.72%
Rate of Compensation Increase				3.50%	3.50%
Interest Rate Credit for Determining Projected Cash Balance Account				3.00%	3.00%
Interest Rate Credit for Determining Projected Cash Balance Account, Segment One				0.53%
Interest Rate Credit for Determining Projected Cash Balance Account, Segment Two				2.31%
Interest Rate Credit for Determining Projected Cash Balance Account, Segment Three				3.09%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment One				0.53%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment Two				2.31%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment Three				3.09%
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Discount Rate	3.72%	4.81%	4.24%
Expected Long-Term Return on Plan Assets	6.50%	6.50%	6.50%
Rate of Compensation Increase	3.50%	3.50%	3.50%
Interest Rate Credit for Determining Projected Cash Balance Account	3.00%	3.00%	3.00%
Interest Rate to Annuitize Cash Balance Account, Segment One	0.53%
Interest Rate to Annuitize Cash Balance Account, Segment Two	2.31%
Interest Rate to Annuitize Cash Balance Account, Segment Three	3.09%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment One	0.53%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment Two	2.31%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment Three	3.09%
Fair Value of Plan Assets	$ 57,051,000	$ 57,051,000	$ 48,445,000	$ 59,837,000	$ 57,051,000
Expected Future Benefit Payments
2021				2,739,000
2022				2,604,000
2023				3,235,000
2024				3,068,000
2025				3,417,000
2026 - 2030				15,146,000
Estimated Contributions During 2021				$ 0
Select Executive Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Assumptions used calculating benefit obligation, interest rate to annuitize cash balance account				2.31%
Defined benefit plan, amortization of service cost	12 years 6 months
Defined benefit plan, benefit obligation, period increase (decrease)	$ 122,797
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0	0	$ 0	0
Benefit Obligation	5,194,000	5,194,000	4,710,000	5,820,000	5,194,000
Funded Status of Plan				(5,820,000)	(5,194,000)
Change in Benefit Obligation
Benefit Obligation, Beginning of Period	5,194,000	4,710,000
Service Cost	408,000	324,000	414,000
Interest Cost	192,000	217,000	192,000
Plan Participants' Contributions	0	0
Amendments	122,000
Actuarial Loss	369,000	409,000
Benefits Paid	(465,000)	(466,000)
Benefit Obligation, End of Period	5,820,000	5,194,000	4,710,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0	0
Actual Return on Plan Assets	0	0
Employer Contributions	465,000	466,000
Plan Participants' Contributions	0	0
Benefits Paid	(465,000)	(466,000)
Fair Value of Plan Assets, End of Period	0	0	0
Accumulated Benefit Obligation at December 31, 2020				5,740,000
Amounts Recognized in the Consolidated Balance Sheets
Prepaid Pension Asset				0	0
Accrued Benefit Liability				(5,820,000)	(5,194,000)
Net Benefit Recognized				(5,820,000)	(5,194,000)
Amounts Recognized in Other Comprehensive Income (Loss)
Net Unamortized (Gain) Loss Arising During the Period	368,000	409,000	(17,000)
Net Prior Service Cost Arising During the Period	123,000		0
Amortization of Net (Loss) Gain	(146,000)	(113,000)	(131,000)
Amortization of Prior Service Credit	(42,000)	(54,000)	(57,000)
Total Other Comprehensive Income for Pension and Other Postretirement Benefit Plans	303,000	242,000	(205,000)
Accumulated Other Comprehensive Income
Net Actuarial Loss (Gains)				2,497,000	2,275,000
Prior Service Cost				459,000	378,000
Total Accumulated Other Comprehensive Income, Before Tax				2,956,000	$ 2,653,000
Amounts that will be Amortized from Accumulated Other Comprehensive Income the Next Year
Net Actuarial Loss				153,000
Prior Service Cost				$ 48,000
Net Periodic Benefit Cost
Service Cost	408,000	324,000	414,000
Interest Cost	192,000	217,000	192,000
Expected Return on Plan Assets	0	0	0
Amortization of Prior Service (Credit) Cost	42,000	54,000	57,000
Amortization of Net Loss	146,000	113,000	131,000
Net Periodic Benefit Cost	$ 788,000	$ 708,000	$ 794,000
Weighted-Average Assumptions Used in Calculating Benefit Obligation
Discount Rate				3.19%	3.75%
Rate of Compensation Increase				3.50%	3.50%
Interest Rate Credit for Determining Projected Cash Balance Account				3.00%	3.00%
Interest Rate Credit for Determining Projected Cash Balance Account, Segment One				0.53%
Interest Rate Credit for Determining Projected Cash Balance Account, Segment Two				2.31%
Interest Rate Credit for Determining Projected Cash Balance Account, Segment Three				3.09%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment One				0.53%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment Two				2.31%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment Three				3.09%
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Discount Rate	3.75%	4.80%	4.18%
Rate of Compensation Increase	3.50%	3.50%	3.50%
Interest Rate Credit for Determining Projected Cash Balance Account	3.00%	3.00%	3.00%
Interest Rate to Annuitize Cash Balance Account, Segment One	0.53%
Interest Rate to Annuitize Cash Balance Account, Segment Two	2.31%
Interest Rate to Annuitize Cash Balance Account, Segment Three	3.09%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment One	0.53%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment Two	2.31%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Amounts, Segment Three	3.09%
Fair Value of Plan Assets	$ 0	$ 0	$ 0	$ 0	$ 0
Expected Future Benefit Payments
2021				453,000
2022				433,000
2023				412,000
2024				580,000
2025				559,000
2026 - 2030				2,476,000
Estimated Contributions During 2021				$ 453,000
Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Assumptions used calculating benefit obligation, interest rate to annuitize cash balance account				3.09%
Defined Benefit Plan Funded Status
Fair Value of Plan Assets	0	0	0	$ 0	0
Benefit Obligation	9,028,000	7,706,000	7,706,000	9,028,000	8,652,000
Funded Status of Plan				(9,028,000)	(8,652,000)
Change in Benefit Obligation
Benefit Obligation, Beginning of Period	8,652,000	7,706,000
Service Cost	123,000	121,000	136,000
Interest Cost	310,000	364,000	333,000
Plan Participants' Contributions	454,000	485,000
Amendments	0
Actuarial Loss	151,000	670,000
Benefits Paid	(662,000)	(694,000)
Benefit Obligation, End of Period	9,028,000	8,652,000	7,706,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, Beginning of Period	0	0
Actual Return on Plan Assets	0	0
Employer Contributions	208,000	209,000
Plan Participants' Contributions	454,000	485,000
Benefits Paid	(662,000)	(694,000)
Fair Value of Plan Assets, End of Period	0	0	0
Accumulated Benefit Obligation at December 31, 2020				9,028,000
Amounts Recognized in the Consolidated Balance Sheets
Prepaid Pension Asset				0	0
Accrued Benefit Liability				(9,028,000)	(8,652,000)
Net Benefit Recognized				(9,028,000)	(8,652,000)
Amounts Recognized in Other Comprehensive Income (Loss)
Net Unamortized (Gain) Loss Arising During the Period	151,000	670,000	(665,000)
Net Prior Service Cost Arising During the Period	0		453,000
Amortization of Net (Loss) Gain	0	42,000	0
Amortization of Prior Service Credit	(106,000)	(101,000)	(100,000)
Total Other Comprehensive Income for Pension and Other Postretirement Benefit Plans	45,000	611,000	(312,000)
Accumulated Other Comprehensive Income
Net Actuarial Loss (Gains)				(30,000)	(181,000)
Prior Service Cost				578,000	685,000
Total Accumulated Other Comprehensive Income, Before Tax				548,000	$ 504,000
Amounts that will be Amortized from Accumulated Other Comprehensive Income the Next Year
Net Actuarial Loss				30,000
Prior Service Cost				$ 106,000
Net Periodic Benefit Cost
Service Cost	123,000	121,000	136,000
Interest Cost	310,000	364,000	333,000
Expected Return on Plan Assets	0	0	0
Amortization of Prior Service (Credit) Cost	106,000	101,000	100,000
Amortization of Net Loss	0	(42,000)	0
Net Periodic Benefit Cost	$ 539,000	$ 544,000	$ 569,000
Weighted-Average Assumptions Used in Calculating Benefit Obligation
Discount Rate				3.17%	3.76%
Rate of Compensation Increase				3.50%	3.50%
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Discount Rate	3.76%	4.81%	4.22%
Rate of Compensation Increase	3.50%	3.50%	3.50%
Fair Value of Plan Assets	$ 0	$ 0	$ 0	$ 0	$ 0
Expected Future Benefit Payments
2021				694,000
2022				684,000
2023				664,000
2024				663,000
2025				675,000
2026 - 2030				3,280,000
Estimated Contributions During 2021				$ 694,000
Minimum | Cash
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				0.00%	0.00%
Minimum | Interest-Bearing Money Market Fund
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				0.00%	0.00%
Minimum | Common Stock
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				0.00%	0.00%
Minimum | North Country Funds - Equity
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage
Minimum | Other Mutual Funds - Equity
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage
Minimum | Equity Funds
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				55.00%	55.00%
Minimum | North Country Funds - Fixed Income
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage
Minimum | Other Mutual Funds - Fixed Income
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage
Minimum | Fixed Income Funds
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				10.00%	10.00%
Minimum | Alternative ETF
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				0.00%	0.00%
Maximum | Cash
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				15.00%	15.00%
Maximum | Interest-Bearing Money Market Fund
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				15.00%	15.00%
Maximum | Common Stock
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				10.00%	10.00%
Maximum | North Country Funds - Equity
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage
Maximum | Other Mutual Funds - Equity
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage
Maximum | Equity Funds
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				85.00%	85.00%
Maximum | North Country Funds - Fixed Income
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage
Maximum | Other Mutual Funds - Fixed Income
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage
Maximum | Fixed Income Funds
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				30.00%	30.00%
Maximum | Alternative ETF
Weighted-Average Assumptions Used in Calculating Net Periodic Benefit Cost
Target Allocation Maximum, Percentage				20.00%	20.00%
Subsequent to January 1, 2003
Defined Benefit Plan Disclosure [Line Items]
Service credits, percent of eligible salaries	6.00%
Prior to January 1, 2003 | Minimum
Defined Benefit Plan Disclosure [Line Items]
Service credits, percent of eligible salaries	6.00%
Prior to January 1, 2003 | Maximum
Defined Benefit Plan Disclosure [Line Items]
Service credits, percent of eligible salaries	12.00%