Retirement Benefit Plans (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017		Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match, maximum		5.00%
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		$ 50,220	$ 50,220		$ 53,571		$ 50,220
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		50,220
Fair Value of Plan Assets, End of Period		53,571	50,220
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		$ 50,220	$ 50,220		$ 53,571		$ 50,220
Percent of Total					100.00%		100.00%
Expected Future Benefit Payments [Abstract]
Health Care Cost Trend Rate Assumed for Next Year		7.25%	7.50%
Rate to which the Cost Trend Rate is Assumed to Decline (the Ultimate Trend Rate)		3.89%	3.89%
Year that the Rate Reaches the Ultimate Trend Rate					2075		2075
Effect of One Percentage Point Increase on Service and Interest Cost Components		$ 44
Effect of One Percentage Point Decrease on Service and Interest Cost Components		(37)
Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation		516
Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation		(445)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		50,220	$ 50,220		$ 53,571		$ 50,220
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		50,220
Fair Value of Plan Assets, End of Period		53,571	50,220
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		50,220	50,220		53,571		50,220
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Cash and Cash Equivalents [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		40	40		22		40
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		40
Fair Value of Plan Assets, End of Period		22	40
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		$ 40	$ 40		$ 22		$ 40
Percent of Total					0.00%		0.10%
Target Allocation Minimum, Percentage		0.00%	0.00%
Target Allocation Maximum, Percentage		15.00%	15.00%
Cash and Cash Equivalents [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		$ 40	$ 40		$ 22		$ 40
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		40
Fair Value of Plan Assets, End of Period		22	40
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		40	40		22		40
Cash and Cash Equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Cash and Cash Equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Money Market Funds [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		3,080	3,080		2,682		3,080
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		3,080
Fair Value of Plan Assets, End of Period		2,682	3,080
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		$ 3,080	$ 3,080		$ 2,682		$ 3,080
Percent of Total					5.00%		6.10%
Target Allocation Minimum, Percentage		0.00%	0.00%
Target Allocation Maximum, Percentage		15.00%	15.00%
Money Market Funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		$ 3,080	$ 3,080		$ 2,682		$ 3,080
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		3,080
Fair Value of Plan Assets, End of Period		2,682	3,080
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		3,080	3,080		2,682		3,080
Money Market Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Money Market Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Common Stock
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		6,592	6,592		5,657		6,592
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		6,592
Fair Value of Plan Assets, End of Period		5,657	6,592
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		$ 6,592	$ 6,592		$ 5,657		$ 6,592
Percent of Total					10.60%	[1]	13.10%
Target Allocation Minimum, Percentage		0.00%	0.00%
Target Allocation Maximum, Percentage		10.00%	10.00%
Common Stock | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		$ 6,592	$ 6,592		$ 5,657		$ 6,592
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		6,592
Fair Value of Plan Assets, End of Period		5,657	6,592
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		6,592	6,592		5,657		6,592
Common Stock | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Common Stock | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Equity Funds [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		32,200	32,200		34,848		32,200
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		32,200
Fair Value of Plan Assets, End of Period		34,848	32,200
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		$ 32,200	$ 32,200		$ 34,848		$ 32,200
Percent of Total					65.00%		64.20%
Target Allocation Minimum, Percentage		55.00%	55.00%
Target Allocation Maximum, Percentage		85.00%	85.00%
Equity Funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		$ 32,200	$ 32,200		$ 34,848		$ 32,200
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		32,200
Fair Value of Plan Assets, End of Period		34,848	32,200
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		32,200	32,200		34,848		32,200
Equity Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Equity Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Equity Funds [Member] | North Country Funds - Equity [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets	[2]	18,640	18,640		19,680		18,640
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period	[2]	18,640
Fair Value of Plan Assets, End of Period	[2]	19,680	18,640
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets	[2]	$ 18,640	$ 18,640		$ 19,680		$ 18,640
Percent of Total	[2]				36.70%		37.20%
Target Allocation Minimum, Percentage
Target Allocation Maximum, Percentage
Equity Funds [Member] | North Country Funds - Equity [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets	[2]	$ 18,640	$ 18,640		$ 19,680		$ 18,640
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period	[2]	18,640
Fair Value of Plan Assets, End of Period	[2]	19,680	18,640
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets	[2]	18,640	18,640		19,680		18,640
Equity Funds [Member] | North Country Funds - Equity [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets	[2]	0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period	[2]	0
Fair Value of Plan Assets, End of Period	[2]	0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets	[2]	0	0		0		0
Equity Funds [Member] | North Country Funds - Equity [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets	[2]	0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period	[2]	0
Fair Value of Plan Assets, End of Period	[2]	0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets	[2]	0	0		0		0
Equity Funds [Member] | Other Mutual Funds - Equity [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		13,560	13,560		15,168		13,560
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		13,560
Fair Value of Plan Assets, End of Period		15,168	13,560
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		$ 13,560	$ 13,560		$ 15,168		$ 13,560
Percent of Total					28.30%		27.00%
Target Allocation Minimum, Percentage
Target Allocation Maximum, Percentage
Equity Funds [Member] | Other Mutual Funds - Equity [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		$ 13,560	$ 13,560		$ 15,168		$ 13,560
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		13,560
Fair Value of Plan Assets, End of Period		15,168	13,560
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		13,560	13,560		15,168		13,560
Equity Funds [Member] | Other Mutual Funds - Equity [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Equity Funds [Member] | Other Mutual Funds - Equity [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Fixed Income Funds [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		8,308	8,308		10,362		8,308
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		8,308
Fair Value of Plan Assets, End of Period		10,362	8,308
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		$ 8,308	$ 8,308		$ 10,362		$ 8,308
Percent of Total					19.40%		16.50%
Target Allocation Minimum, Percentage		10.00%	10.00%
Target Allocation Maximum, Percentage		30.00%	30.00%
Fixed Income Funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		$ 8,308	$ 8,308		$ 10,362		$ 8,308
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		8,308
Fair Value of Plan Assets, End of Period		10,362	8,308
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		8,308	8,308		10,362		8,308
Fixed Income Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Fixed Income Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Fixed Income Funds [Member] | North Country Funds - Fixed Income [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets	[2]	7,332	7,332		8,388		7,332
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period	[2]	7,332
Fair Value of Plan Assets, End of Period	[2]	8,388	7,332
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets	[2]	$ 7,332	$ 7,332		$ 8,388		$ 7,332
Percent of Total	[2]				15.70%		14.60%
Target Allocation Minimum, Percentage
Target Allocation Maximum, Percentage
Fixed Income Funds [Member] | North Country Funds - Fixed Income [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets	[2]	$ 7,332	$ 7,332		$ 8,388		$ 7,332
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period	[2]	7,332
Fair Value of Plan Assets, End of Period	[2]	8,388	7,332
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets	[2]	7,332	7,332		8,388		7,332
Fixed Income Funds [Member] | North Country Funds - Fixed Income [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets	[2]	0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period	[2]	0
Fair Value of Plan Assets, End of Period	[2]	0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets	[2]	0	0		0		0
Fixed Income Funds [Member] | North Country Funds - Fixed Income [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets	[2]	0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period	[2]	0
Fair Value of Plan Assets, End of Period	[2]	0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets	[2]	0	0		0		0
Fixed Income Funds [Member] | Other Mutual Funds - Fixed Income [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		976	976		1,974		976
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		976
Fair Value of Plan Assets, End of Period		1,974	976
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		$ 976	$ 976		$ 1,974		$ 976
Percent of Total					3.70%		1.90%
Target Allocation Minimum, Percentage
Target Allocation Maximum, Percentage
Fixed Income Funds [Member] | Other Mutual Funds - Fixed Income [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		$ 976	$ 976		$ 1,974		$ 976
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		976
Fair Value of Plan Assets, End of Period		1,974	976
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		976	976		1,974		976
Fixed Income Funds [Member] | Other Mutual Funds - Fixed Income [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Fixed Income Funds [Member] | Other Mutual Funds - Fixed Income [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0		0		0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0
Fair Value of Plan Assets, End of Period		0	0
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Fair Value of Plan Assets		0	0		0		0
Employees' Pension Plan [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		50,220	47,234	$ 47,234	53,571		50,220
Benefit Obligation		36,154	35,982	35,982	38,921		36,154
Funded Status of Plan					14,650		14,066
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning of Period		36,154	35,982
Service Cost		1,392	1,400	1,503
Interest Cost		1,682	1,641	1,545
Plan Participants' Contributions		0	0
Amendments		0	0
Actuarial Loss		2,440	(738)
Benefits Paid		(2,747)	(2,131)
Benefit Obligation, End of Period		38,921	36,154	35,982
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		50,220	47,234
Actual Return on Plan Assets		6,098	5,117
Contributions to Pension Plans		0	0
Plan Participants' Contributions		0	0
Benefits Paid		(2,747)	(2,131)
Fair Value of Plan Assets, End of Period		53,571	50,220	47,234
Accumulated Benefit Obligation at December 31, 2012					38,557
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Prepaid Benefit Cost					14,650		14,066
Accrued Benefit Liability					0		0
Net Benefit Cost Recognized					14,650		14,066
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Retirement Plan Loss, Before-Tax Amount		(517)	(2,657)	472
Net prior Service Cost Arising During the Period		0	0	277
Amortization of Net Loss		(306)	(591)	(601)
Accretion of Net Retirement Plan Prior Service Credit, Tax (Expense) Benefit		57	57	83
Total Other Comprehensive (Loss) Income for Pension and Other Postretirement Benefit Plans		(766)	(3,191)	231
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Net Actuarial Loss					6,656		7,479
Prior Service (Credit) Cost					264		207
Total Accumulated Other Comprehensive Income, Before Tax					$ 6,920		$ 7,686
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Net Actuarial Loss		131
Prior Service (Credit) Cost		(49)
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost		1,392	1,400	1,503
Interest Cost		1,682	1,641	1,545
Expected Return on Plan Assets		(3,141)	(3,198)	(3,311)
Amortization of Prior Service (Credit) Cost		(57)	(57)	(83)
Amortization of Net Loss		306	591	601
Net Periodic Benefit Cost		$ 182	$ 377	$ 255
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount Rate					4.24%		4.83%
Rate of Compensation Increase					3.50%		3.50%
Interest Rate Credit for Determining Projected Cash Balance Account					3.00%		3.00%
Interest Rate to Annuitize Cash Balance Account					4.25%		4.50%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Account					4.25%		4.50%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount Rate		4.83%	4.73%	4.31%
Expected Long-Term Return on Assets		6.50%	7.00%	7.50%
Rate of Compensation Increase		3.50%	3.50%	3.50%
Interest Rate Credit for Determining Projected Cash Balance Account		3.00%	3.03%	3.04%
Interest Rate to Annuitize Cash Balance Account		4.50%	5.00%	4.75%
Interest Rate to Convert Accuities to Actuarially Equivalent Lump Sum Amounts		4.50%	5.00%	4.75%
Fair Value of Plan Assets		$ 50,220	$ 47,234	$ 47,234	$ 53,571		$ 50,220
Expected Future Benefit Payments [Abstract]
2018					3,434
2019					2,345
2020					2,885
2021					2,456
2022					2,589
2022- 2026					14,107
Estimated Contributions During 2015		0
Select Executive Retirement Plan [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0	0	0		0
Benefit Obligation		4,547	4,784	4,784	4,586		4,547
Funded Status of Plan					(4,586)		(4,547)
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning of Period		4,547	4,784
Service Cost		45	40	32
Interest Cost		209	206	211
Plan Participants' Contributions		0	0
Amendments		0	0
Actuarial Loss		245	(31)
Benefits Paid		(460)	(452)
Benefit Obligation, End of Period		4,586	4,547	4,784
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0	0
Actual Return on Plan Assets		0	0
Contributions to Pension Plans		460	452
Plan Participants' Contributions		0	0
Benefits Paid		(460)	(452)
Fair Value of Plan Assets, End of Period		0	0	0
Accumulated Benefit Obligation at December 31, 2012					4,586
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Prepaid Benefit Cost					0		0
Accrued Benefit Liability					(4,586)		(4,547)
Net Benefit Cost Recognized					(4,586)		(4,547)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Retirement Plan Loss, Before-Tax Amount		244	(32)	(152)
Net prior Service Cost Arising During the Period		0	0	91
Amortization of Net Loss		(129)	(125)	(131)
Accretion of Net Retirement Plan Prior Service Credit, Tax (Expense) Benefit		(57)	(57)	(58)
Total Other Comprehensive (Loss) Income for Pension and Other Postretirement Benefit Plans		58	(214)	(250)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Net Actuarial Loss					2,127		2,012
Prior Service (Credit) Cost					489		546
Total Accumulated Other Comprehensive Income, Before Tax					$ 2,616		$ 2,558
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Net Actuarial Loss		133
Prior Service (Credit) Cost		57
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost		45	40	32
Interest Cost		209	206	211
Expected Return on Plan Assets		0	0	0
Amortization of Prior Service (Credit) Cost		57	57	58
Amortization of Net Loss		129	125	131
Net Periodic Benefit Cost		$ 440	$ 428	$ 432
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount Rate					4.18%		4.73%
Rate of Compensation Increase					3.50%		3.50%
Interest Rate Credit for Determining Projected Cash Balance Account					3.00%		3.00%
Interest Rate to Annuitize Cash Balance Account					4.25%		4.50%
Interest Rate to Convert Annuities to Actuarially Equivalent Lump Sum Account					4.25%		4.50%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount Rate		4.73%	4.61%	4.26%
Rate of Compensation Increase		3.50%	3.50%	3.50%
Interest Rate Credit for Determining Projected Cash Balance Account		3.00%	3.03%
Interest Rate to Annuitize Cash Balance Account		4.50%	5.00%
Interest Rate to Convert Accuities to Actuarially Equivalent Lump Sum Amounts		4.50%	5.00%	4.75%
Fair Value of Plan Assets		$ 0	$ 0	$ 0	$ 0		$ 0
Expected Future Benefit Payments [Abstract]
2018					439
2019					426
2020					411
2021					396
2022					380
2022- 2026					1,752
Estimated Contributions During 2015		439
Postretirement Benefit Plans [Member]
Defined Benefit Plan, Funded Status of Plan [Abstract]
Fair Value of Plan Assets		0	0	0	0		0
Benefit Obligation		7,623	7,701	7,701	7,727		7,623
Funded Status of Plan					(7,727)		(7,623)
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning of Period		7,623	7,701
Service Cost		130	147	250
Interest Cost		339	340	394
Plan Participants' Contributions		492	402
Amendments		0	0
Actuarial Loss		(14)	(327)
Benefits Paid		(843)	(640)
Benefit Obligation, End of Period		7,727	7,623	7,701
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning of Period		0	0
Actual Return on Plan Assets		0	0
Contributions to Pension Plans		351	238
Plan Participants' Contributions		492	402
Benefits Paid		(843)	(640)
Fair Value of Plan Assets, End of Period		0	0	0
Accumulated Benefit Obligation at December 31, 2012					7,727
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Prepaid Benefit Cost					0		0
Accrued Benefit Liability					(7,727)		(7,623)
Net Benefit Cost Recognized					(7,727)		(7,623)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Retirement Plan Loss, Before-Tax Amount		(14)	(328)	(1,715)
Net prior Service Cost Arising During the Period		0	0	0
Amortization of Net Loss		24	0	(114)
Accretion of Net Retirement Plan Prior Service Credit, Tax (Expense) Benefit		11	12	31
Total Other Comprehensive (Loss) Income for Pension and Other Postretirement Benefit Plans		21	(316)	(1,798)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Net Actuarial Loss					(228)		(238)
Prior Service (Credit) Cost					433		422
Total Accumulated Other Comprehensive Income, Before Tax					$ 205		$ 184
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Net Actuarial Loss		(2)
Prior Service (Credit) Cost		48
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost		130	147	250
Interest Cost		339	340	394
Expected Return on Plan Assets		0	0	0
Amortization of Prior Service (Credit) Cost		(11)	(12)	(31)
Amortization of Net Loss		(24)	0	114
Net Periodic Benefit Cost		$ 434	$ 475	$ 727
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount Rate					4.22%		4.80%
Rate of Compensation Increase					3.50%		3.50%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount Rate		4.80%	4.69%	4.31%
Rate of Compensation Increase		3.50%	3.50%	3.50%
Fair Value of Plan Assets		$ 0	$ 0	$ 0	$ 0		$ 0
Expected Future Benefit Payments [Abstract]
2018					524
2019					543
2020					540
2021					581
2022					574
2022- 2026					$ 2,917
Estimated Contributions During 2015		$ 524
Subsequent to January 1, 2003 [Member]
Defined Benefit Plan Disclosure [Line Items]
Service credits, percent of eligible salaries		6.00%
Prior to January 1, 2003 [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Service credits, percent of eligible salaries		6.00%
Prior to January 1, 2003 [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Service credits, percent of eligible salaries		12.00%

[1] Acquisition of Arrow Financial Corporation common stock was under 10% of the total fair value of the employee's pension plan assets at the time of acquisition.

[2] The North Country Funds - Equity and the North Country Funds - Fixed Income are publicly traded mutual funds advised by Arrow's subsidiary, North Country Investment Advisers, Inc.