INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2015

Notes To Consolidated Financial Statements [Abstract]

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

Eversource	For the Years Ended December 31,
(Millions of Dollars)	2015		2014		2013
Current Income Taxes:
Federal	$	6.2	$	4.4	$	8.8
State		45.7		24.5		(9.4)
Total Current		51.9		28.9		(0.6)
Deferred Income Taxes, Net:
Federal		436.1		406.8		386.2
State		55.6		36.5		45.4
Total Deferred		491.7		443.3		431.6
Investment Tax Credits, Net		(3.6)		(3.9)		(4.1)
Income Tax Expense	$	540.0	$	468.3	$	426.9

		For the Years Ended December 31,
		2015								2014								2013
				NSTAR								NSTAR								NSTAR
(Millions of Dollars)		CL&P		Electric		PSNH		WMECO		CL&P		Electric		PSNH		WMECO		CL&P		Electric		PSNH		WMECO
Current Income Taxes:
	Federal	$	26.9	$	36.3	$	(16.7)	$	(3.5)	$	(0.2)	$	75.0	$	(22.6)	$	1.9	$	20.1	$	95.8	$	(8.2)	$	(53.4)
	State		15.8		19.8		6.0		1.6		4.3		20.2		(0.1)		1.8		(6.7)		29.6		3.6		4.2
Total Current			42.7		56.1		(10.7)		(1.9)		4.1		95.2		(22.7)		3.7		13.4		125.4		(4.6)		(49.2)
Deferred Income Taxes, Net:
	Federal		135.8		147.5		74.5		33.4		138.0		88.0		79.6		28.1		114.9		49.8		64.5		84.7
	State		0.2		25.7		9.3		6.0		(7.1)		20.1		15.2		6.0		15.1		(1.0)		11.2		2.3
Total Deferred			136.0		173.2		83.8		39.4		130.9		108.1		94.8		34.1		130.0		48.8		75.7		87.0
Investment Tax Credits, Net			(1.3)		(1.3)		-		(0.5)		(1.5)		(1.3)		-		(0.5)		(1.7)		(1.3)		-		(0.4)
Income Tax Expense		$	177.4	$	228.0	$	73.1	$	37.0	$	133.5	$	202.0	$	72.1	$	37.3	$	141.7	$	172.9	$	71.1	$	37.4

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

A reconciliation between income tax expense and the expected tax expense at the statutory rate is as follows:
Eversource		For the Years Ended December 31,
(Millions of Dollars, except percentages)		2015		2014		2013
Income Before Income Tax Expense		$	1,425.9	$	1,295.4	$	1,220.6
Statutory Federal Income Tax Expense at 35%			499.1		453.4		427.2
Tax Effect of Differences:
	Depreciation		(4.6)		(5.6)		(7.4)
	Investment Tax Credit Amortization		(3.6)		(3.9)		(4.1)
	Other Federal Tax Credits		(3.8)		(3.5)		(3.7)
	State Income Taxes, Net of Federal Impact		61.1		42.5		27.6
	Dividends on ESOP		(8.1)		(8.0)		(8.0)
	Tax Asset Valuation Allowance/Reserve Adjustments		4.7		(2.9)		(4.3)
	Other, Net		(4.8)		(3.7)		(0.4)
Income Tax Expense		$	540.0	$	468.3	$	426.9
Effective Tax Rate			37.9%		36.2%		35.0%

		For the Years Ended December 31,
		2015								2014								2013
(Millions of Dollars,				NSTAR								NSTAR								NSTAR
	except percentages)	CL&P		Electric		PSNH		WMECO		CL&P		Electric		PSNH		WMECO		CL&P		Electric		PSNH		WMECO
Income Before Income Tax Expense		$	476.8	$	572.6	$	187.5	$	93.5	$	421.2	$	505.1	$	186.1	$	95.1	$	421.1	$	441.4	$	182.5	$	97.8
Statutory Federal Income Tax Expense at 35%			166.9		200.4		65.6		32.7		147.4		176.8		65.1		33.3		147.4		154.5		63.9		34.2
Tax Effect of Differences:
	Depreciation		(1.7)		(1.4)		0.5		(0.3)		(3.6)		(1.3)		0.3		(0.2)		(7.0)		0.1		0.6		-
	Investment Tax Credit Amortization		(1.3)		(1.3)		-		(0.5)		(1.5)		(1.3)		-		(0.5)		(1.7)		(1.3)		-		(0.4)
	Other Federal Tax Credits		-		-		(3.8)		-		-		-		(3.5)		-		-		-		(3.7)		-
	State Income Taxes, Net of Federal Impact		9.2		29.6		9.9		4.9		4.4		26.2		9.8		5.0		5.0		18.6		9.6		4.2
	Tax Asset Valuation Allowance/ Reserve Adjustments		1.2		-		-		-		(6.3)		-		-		-		0.4		-		-		-
	Other, Net		3.1		0.7		0.9		0.2		(6.9)		1.6		0.4		(0.3)		(2.4)		1.0		0.7		(0.6)
Income Tax Expense		$	177.4	$	228.0	$	73.1	$	37.0	$	133.5	$	202.0	$	72.1	$	37.3	$	141.7	$	172.9	$	71.1	$	37.4
Effective Tax Rate			37.2%		39.8%		39.0%		39.6%		31.7%		40.0%		38.7%		39.2%		33.6%		39.2%		39.0%		38.2%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

Eversource			As of December 31,
(Millions of Dollars)			2015		2014
Deferred Tax Assets:
	Employee Benefits		$	637.5	$	632.2
	Derivative Liabilities			172.7		199.6
	Regulatory Deferrals - Liabilities			243.5		366.7
	Allowance for Uncollectible Accounts			60.5		60.5
	Tax Effect - Tax Regulatory Liabilities			9.7		10.0
	Federal Net Operating Loss Carryforwards			5.4		59.1
	Purchase Accounting Adjustment			119.3		126.2
	Other			197.1		198.7
Total Deferred Tax Assets				1,445.7		1,653.0
	Less: Valuation Allowance			3.7		5.1
Net Deferred Tax Assets			$	1,442.0	$	1,647.9
Deferred Tax Liabilities:
	Accelerated Depreciation and Other Plant-Related Differences		$	4,602.6	$	4,215.9
	Property Tax Accruals			76.7		109.6
	Regulatory Amounts:
		Regulatory Deferrals - Assets		1,289.1		1,277.9
		Tax Effect - Tax Regulatory Assets		249.3		240.2
		Goodwill Regulatory Asset - 1999 Merger		194.9		203.2
		Derivative Assets		17.7		32.6
		Other		159.4		196.3
Total Deferred Tax Liabilities			$	6,589.7	$	6,275.7

			As of December 31,
			2015								2014
					NSTAR								NSTAR
(Millions of Dollars)			CL&P		Electric		PSNH		WMECO		CL&P		Electric		PSNH		WMECO
Deferred Tax Assets:
	Employee Benefits		$	126.1	$	91.3	$	37.1	$	10.0	$	129.0	$	39.9	$	46.8	$	9.2
	Derivative Liabilities			165.7		0.6		-		-		193.0		1.8		-		-
	Regulatory Deferrals - Liabilities			36.0		109.4		42.1		6.1		73.9		181.3		46.5		11.4
	Allowance for Uncollectible Accounts			30.4		8.5		3.6		4.5		32.3		13.8		3.2		3.8
	Tax Effect - Tax Regulatory Liabilities			3.1		1.5		2.3		2.4		3.1		1.8		2.1		2.5
	Federal Net Operating Loss Carryforwards			-		-		2.4		0.4		-		-		32.1		4.5
	Other			55.5		3.4		61.1		5.0		53.8		19.9		48.9		4.9
Total Deferred Tax Assets				416.8		214.7		148.6		28.4		485.1		258.5		179.6		36.3
	Less: Valuation Allowance			3.1		-		-		-		4.0		-		-		-
Net Deferred Tax Assets			$	413.7	$	214.7	$	148.6	$	28.4	$	481.1	$	258.5	$	179.6	$	36.3
Deferred Tax Liabilities:
	Accelerated Depreciation and Other Plant-Related Differences		$	1,545.6	$	1,387.1	$	655.3	$	416.1	$	1,378.6	$	1,296.9	$	596.6	$	385.8
	Property Tax Accruals			27.3		22.8		7.3		10.6		58.1		25.0		7.4		12.8
	Regulatory Amounts:
		Regulatory Deferrals - Assets		456.8		339.7		137.9		60.5		502.3		276.0		147.6		60.4
		Tax Effect - Tax Regulatory Assets		168.7		36.0		15.4		9.0		166.9		35.5		15.9		9.3
		Goodwill Regulatory Asset - 1999 Merger		-		167.4		-		-		-		174.4		-		-
		Derivative Assets		17.7		-		-		-		32.6		-		-		-
		Other		18.5		22.0		38.6		2.7		19.4		33.5		35.6		2.8
Total Deferred Tax Liabilities			$	2,234.6	$	1,975.0	$	854.5	$	498.9	$	2,157.9	$	1,841.3	$	803.1	$	471.1

Summary of Operating Loss Carryforwards [Table Text Block]

Carryforwards: The following tables provide the amounts and expiration dates of state tax credit and loss carryforwards and federal tax credit and net operating loss carryforwards:
	As of December 31, 2015
					NSTAR
(Millions of Dollars)	Eversource		CL&P		Electric		PSNH		WMECO		Expiration Range
Federal Net Operating Loss	$	15.5	$	-	$	-	$	7.0	$	1.0	2032
Federal Tax Credit		26.1		0.1		0.2		15.0		-	2031 - 2035
Federal Charitable Contribution		14.9		-		-		-		-	2016 - 2018
State Tax Credit		101.2		73.8		-		-		-	2015 - 2020
State Charitable Contribution		3.0		-		-		-		-	2015 - 2019
	As of December 31, 2014
					NSTAR
(Millions of Dollars)	Eversource		CL&P		Electric		PSNH		WMECO		Expiration Range
Federal Net Operating Loss	$	168.8	$	-	$	-	$	91.8	$	12.7	2031 - 2032
Federal Tax Credit		16.3		0.1		0.2		11.1		-	2031 - 2034
Federal Charitable Contribution		19.4		-		-		-		-	2016 - 2018
State Tax Credit		99.7		71.0		-		-		-	2014 - 2019
State Loss Carryforwards		40.6		-		-		-		-	2014 - 2034
State Charitable Contribution		2.1		-		-		-		-	2015 - 2018

Summary of Income Tax Contingencies [Table Text Block]

(Millions of Dollars)		Eversource		CL&P
Balance as of January 1, 2013		$	83.1	$	49.0
	Gross Increases - Current Year		8.2		2.1
	Gross Decreases - Prior Year		(1.1)		(0.3)
	Settlements		(49.8)		(39.4)
	Lapse of Statute of Limitations		(2.2)		-
Balance as of December 31, 2013			38.2		11.4
	Gross Increases - Current Year		9.3		2.7
	Gross Increases - Prior Year		0.3		0.2
	Lapse of Statute of Limitations		(1.6)		-
Balance as of December 31, 2014			46.2		14.3
	Gross Increases - Current Year		9.9		2.6
	Gross Increases - Prior Year		0.1		-
	Lapse of Statute of Limitations		(8.2)		(3.4)
Balance as of December 31, 2015		$	48.0	$	13.5

	Other Interest Expense/(Income)						Accrued Interest Expense
	For the Years Ended December 31,						As of December 31,
(Millions of Dollars)	2015		2014		2013		2015		2014
Eversource	$	0.1	$	0.4	$	(8.6)	$	2.0	$	1.9
CL&P		0		-		(4.0)		-		-

Summary of Income Tax Examination [Table Text Block]

Description	Tax Years
Federal	2015
Connecticut	2012 - 2015
Massachusetts	2012 - 2015
New Hampshire	2012 - 2015