Retirement Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2012

Compensation and Retirement Disclosure [Abstract]

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

The following tables set forth changes in the plans’ benefit obligations (projected benefit obligation for pension benefits and accumulated benefit obligation for postretirement benefits) and changes in the plans’ assets and the funded status of the pension plans and other postretirement benefit plan at December 31:

Schedule of Defined Benefit Plan Disclosures
	Employees' Pension Plan			Select Executive Retirement Plan			Postretirement Benefit Plans
Defined Benefit Plan Funded Status
December 31, 2012
Fair Value of Plan Assets	$	39,880		$	—		$	—
Benefit Obligation	37,046			5,324			9,213
Funded Status of Plan	$	2,834		$	(5,324	)	$	(9,213	)
December 31, 2011
Fair Value of Plan Assets	$	39,206		$	—		$	—
Benefit Obligation	35,047			4,529			8,556
Funded Status of Plan	$	4,159		$	(4,529	)	$	(8,556	)
Change in Benefit Obligation
Benefit Obligation, at January 1, 2012	$	35,047		$	4,529		$	8,556
Service Cost	1,467			87			202
Interest Cost	1,436			190			338
Plan Participants' Contributions	—			—			348
Amendments	—			405			—
Actuarial Loss	2,857			441			491
Benefits Paid	(3,761		)	(328		)	(722		)
Benefit Obligation, at December 31, 2012	$	37,046		$	5,324		$	9,213
Benefit Obligation, at January 1, 2011	$	32,337		$	4,319		$	7,873
Service Cost	1,353			81			173
Interest Cost	1,598			222			372
Plan Participants' Contributions	—			—			382
Amendments	191			75			—
Actuarial Loss	1,616			151			505
Benefits Paid	(2,048		)	(319		)	(749		)
Benefit Obligation, at December 31, 2011	$	35,047		$	4,529		$	8,556

Schedule of Defined Benefit Plan Disclosures
	Employees' Pension Plan			Select Executive Retirement Plan			Postretirement Benefit Plans
Change in Fair Value of Plan Assets
Fair Value of Plan Assets, at January 1, 2012	$	39,206		$	—		$	—
Actual Return on Plan Assets	4,435			—			—
Employer Contributions	—			328			374
Plan Participants' Contributions	—			—			348
Benefits Paid	(3,761		)	(328		)	(722		)
Fair Value of Plan Assets, at December 31, 2012	$	39,880		$	—		$	—
Change in Fair Value of Plan Assets, continued
Fair Value of Plan Assets, at January 1, 2011	$	37,319		$	—		$	—
Actual Return (Loss) on Plan Assets	(1,065		)	—			—
Employer Contributions	5,000			319			367
Plan Participants' Contributions	—			—			382
Benefits Paid	(2,048		)	(319		)	(749		)
Fair Value of Plan Assets, at December 31, 2011	$	39,206		$	—		$	—
Accumulated Benefit Obligation at December 31, 2012	$	36,519		$	5,324		$	9,213
Amounts Recognized in the Consolidated Balance Sheets
December 31, 2012
Prepaid Benefit Cost	$	2,834		$	—		—
Accrued Benefit Liability	—			(5,324		)	(9,213		)
Net Benefit Cost Recognized	$	2,834		$	(5,324	)	$	(9,213	)
December 31, 2011
Prepaid Benefit Cost	$	4,159		$	—		—
Accrued Benefit Liability	—			(4,529		)	(8,556		)
Net Benefit Cost Recognized	$	4,159		$	(4,529	)	$	(8,556	)
Amounts Recognized in Other Comprehensive Income
For the Year Ended December 31, 2012
Net Unamortized Loss Arising During the Period	$	1,286		$	441		$	491
Net Prior Service Cost Arising During the Period	—			405			—
Amortization of Net Loss	(1,387		)	(156		)	(134		)
Amortization of Prior Service (Cost) Credit	(41		)	(53		)	114
Total Other Comprehensive (Loss) Income for Pension and      Other Postretirement Benefit Plans	$	(142	)	$	637		$	471
For the Year Ended December 31, 2011
Net Unamortized Loss Arising During the Period	$	5,474		$	151		$	504
Net Prior Service Cost Arising During the Period	191			75			—
Amortization of Net Loss	(778		)	(147		)	(71		)
Amortization of Prior Service (Cost) Credit	(38		)	32			114
Total Other Comprehensive (Loss) Income for Pension and      Other Postretirement Benefit Plans	$	4,849		$	111		$	547
For the Year Ended December 31, 2010
Net Unamortized Loss Arising During the Period	$	1,018		$	339		$	454
Net Prior Service Cost Arising During the Period	—			—			(242		)
Amortization of Net Loss	(899		)	(128		)	(85		)
Amortization of Prior Service (Cost) Credit	(25		)	105			106
Total Other Comprehensive (Loss) Income for Pension and      Other Postretirement Benefit Plans	$	94		$	316		$	233

Schedule of Defined Benefit Plan Disclosures
	Employees' Pension Plan			Select Executive Retirement Plan			Postretirement Benefit Plans
Accumulated Other Comprehensive Income
December 31, 2012
Net Actuarial Loss	$	18,026		$	2,368		$	2,850
Prior Service (Credit) Cost	(218		)	721			(419		)
Total Accumulated Other Comprehensive Income, Before Tax	$	17,808		$	3,089		$	2,431
December 31, 2011
Net Actuarial Loss	$	18,127		$	2,083		$	2,493
Prior Service (Credit) Cost	(177		)	369			(533		)
Total Accumulated Other Comprehensive Income, Before Tax	$	17,950		$	2,452		$	1,960
Amounts that will be Amortized from Accumulated   Other Comprehensive Income the Next Year
Net Actuarial Loss	$	1,246		$	151		$	164
Prior Service (Credit) Cost	$	37		$	78		$	(114	)
Net Periodic Benefit Cost
For the Year Ended December 31, 2012
Service Cost	$	1,467		$	87		$	202
Interest Cost	1,436			190			338
Expected Return on Plan Assets	(2,865		)	—			—
Amortization of Prior Service (Credit) Cost	41			53			(114		)
Amortization of Net Loss	1,387			156			134
Net Periodic Benefit Cost	$	1,466		$	486		$	560
For the Year Ended December 31, 2011
Service Cost	$	1,353		$	81		$	173
Interest Cost	1,598			222			372
Expected Return on Plan Assets	(2,793		)	—			—
Amortization of Prior Service (Credit) Cost	38			(32		)	(114		)
Amortization of Net Loss	778			147			71
Net Periodic Benefit Cost	$	974		$	418		$	502
For the Year Ended December 31, 2010
Service Cost	$	1,185		$	56		$	163
Interest Cost	1,667			235			421
Expected Return on Plan Assets	(2,454		)	—			—
Amortization of Prior Service (Credit) Cost	25			(105		)	(105		)
Amortization of Net Loss	899			128			85
Net Periodic Benefit Cost	$	1,322		$	314		$	564
Weighted-Average Assumptions Used in   Calculating Benefit Obligation
December 31, 2012
Discount Rate	3.55		%	3.15		%	3.55		%
Rate of Compensation Increase	3.50		%	3.50		%	3.50		%
Interest Rate Credit for Determining   Projected Cash Balance Account	3.00		%
Interest Rate to Annuitize Cash       Balance Account	4.50		%
Interest Rate to Convert Annuities To Actuarially   Equivalent Lump Sum Amounts	4.50		%	4.50		%

Schedule of Defined Benefit Plan Disclosures
	Employees' Pension Plan		Select Executive Retirement Plan		Postretirement Benefit Plans
December 31, 2011
Discount Rate	4.05	%	4.05	%	4.05	%
Rate of Compensation Increase	3.50	%	3.50	%	3.50	%
Interest Rate Credit for Determining   Projected Cash Balance Account	3.25	%
Interest Rate to Annuitize Cash       Balance Account	5.00	%
Interest Rate to Convert Annuities To Actuarially   Equivalent Lump Sum Amounts	5.00	%	5.00	%
Weighted-Average Assumptions Used in   Calculating Net Periodic Benefit Cost
December 31, 2012
Discount Rate	4.05	%	4.05	%	4.05	%
Expected Long-Term Return on Plan Assets	7.50	%
Rate of Compensation Increase	3.50	%	3.50	%	3.50	%
Interest Rate Credit for Determining       Projected Cash Balance Account	3.25	%
Interest Rate to Annuitize Cash       Balance Account	5.00	%
Interest Rate to Convert AnnuitiesTo Actuarially   Equivalent Lump Sum Amounts	5.00	%	5.00	%
December 31, 2011
Discount Rate	5.15	%	5.15	%	5.15	%
Expected Long-Term Return on Plan Assets	7.50	%
Rate of Compensation Increase	3.50	%	3.50	%	3.50	%
Interest Rate Credit for Determining       Projected Cash Balance Account	4.25	%
Interest Rate to Annuitize Cash       Balance Account	5.50	%
Interest Rate to Convert AnnuitiesTo Actuarially   Equivalent Lump Sum Amounts	5.50	%	5.50	%
December 31, 2010
Discount Rate	5.80	%	5.80	%	5.80	%
Expected Long-Term Return on Plan Assets	7.50	%
Rate of Compensation Increase	3.50	%	3.50	%	3.50	%
Interest Rate Credit for Determining       Projected Cash Balance Account	4.50	%
Interest Rate to Annuitize Cash       Balance Account	6.00	%
Interest Rate to Convert AnnuitiesTo Actuarially   Equivalent Lump Sum Amounts	6.00	%	6.00	%

Schedule of Defined Benefit Plan Disclosures Information about Defined Benefit Plan Assets - Employees' Pension Plan
	Fair Value Measurements Using:
Asset Category	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total		Percent of Total		Target Allocation Minimum		Target Allocation Maximum
December 31, 2012
Cash	$	17	$	—	$	—	$	17	—	%	—	%	15.0	%
Interest-Bearing Money Market Fund	5,236		—		—		5,236		13.1	%	—	%	15.0	%
Arrow Common Stock1	4,197		—		—		4,197		10.5	%	—	%	10.0	%
North Country Funds - Equity 2	13,043		—		—		13,043		32.8	%
Other Mutual Funds - Equity	11,160		—		—		11,160		28.0	%
Total Equity Funds	24,203		—		—		24,203		60.8	%	55.0	%	85.0	%
North Country Funds - Fixed income 2	4,236		—		—		4,236		10.6	%
Other Mutual Funds - Fixed Income	1,991		—		—		1,991		5.0	%
Total Fixed Income Funds	6,227		—		—		6,227		15.6	%	10.0	%	30.0	%
Total	$	39,880	$	—	$	—	$	39,880	100.0	%
December 31, 2011
Cash	$	7	$	—	$	—	$	7	—	%	—	%	15.0	%
Interest-Bearing Money Market Fund	1,857		—		—		1,857		4.7	%	—	%	15.0	%
Arrow Common Stock	3,843		—		—		3,843		9.8	%	—	%	10.0	%
North Country Funds - Equity 2	13,259		—		—		13,259		33.9	%
Other Mutual Funds - Equity	14,908		—		—		14,908		38.0	%
Total Equity Funds	28,167		—		—		28,167		71.9	%	55.0	%	85.0	%
North Country Funds - Fixed income 2	4,151		—		—		4,151		10.6	%
Other Mutual Funds - Fixed Income	1,181		—		—		1,181		3.0	%
Total Fixed Income Funds	5,332		—		—		5,332		13.6	%	10.0	%	30.0	%
Total	$	39,206	$	—	$	—	$	39,206	100.0	%