DERIVATIVE INSTRUMENTS (Tables)

3 Months Ended

Mar. 31, 2015

Notes To Consolidated Financial Statements [Abstract]

Schedule Of Derivative Instruments In Statement Of Financial Position Fair Value Text Block

		As of March 31, 2015						As of December 31, 2014
		Commodity Supply				Net Amount		Commodity Supply				Net Amount
		and Price Risk				Recorded as		and Price Risk					Recorded as
(Millions of Dollars)		Management		Netting (1)		a Derivative		Management		Netting (1)		a Derivative
Current Derivative Assets:
Level 3:
	ES	$	16.0	$	(6.6)	$	9.4	$	16.2	$	(6.6)	$	9.6
	CL&P		16.0		(6.6)		9.4		16.1		(6.6)		9.5
	NSTAR Electric		-		-		-		0.1		-		0.1
Long-Term Derivative Assets:
Level 3:
	ES, CL&P	$	88.3	$	(17.8)	$	70.5	$	93.5	$	(19.2)	$	74.3
Current Derivative Liabilities:
Level 2:
	ES	$	(3.2)	$	-	$	(3.2)	$	(9.8)	$	-	$	(9.8)
Level 3:
	ES		(90.3)		-		(90.3)		(90.0)		-		(90.0)
	CL&P		(88.2)		-		(88.2)		(88.5)		-		(88.5)
	NSTAR Electric		(2.1)		-		(2.1)		(1.5)		-		(1.5)
Long-Term Derivative Liabilities:
Level 2:
	ES	$	(0.2)	$	-	$	(0.2)	$	(0.3)	$	-	$	(0.3)
Level 3:
	ES		(396.4)		-		(396.4)		(409.3)		-		(409.3)
	CL&P		(395.0)		-		(395.0)		(406.2)		-		(406.2)
	NSTAR Electric		(1.4)		-		(1.4)		(3.1)		-		(3.1)

Rollforward Of Net Derivative Asset Liabilities Valued Using Unobservable Inputs [Table Text Block]

	For the Three Months Ended March 31,
	2015						2014
					NSTAR						NSTAR
(Millions of Dollars)	ES		CL&P		Electric		ES		CL&P		Electric
Derivatives, Net:
Fair Value as of Beginning of Period	$	(415.4)	$	(410.9)	$	(4.5)	$	(635.2)	$	(630.6)	$	(7.3)
Net Realized/Unrealized Gains/(Losses) Included in Regulatory Assets and Liabilities		(12.1)		(12.1)		-		49.2		52.0		(0.1)
Settlements		20.7		19.7		1.0		21.7		21.6		0.1
Fair Value as of End of Period	$	(406.8)	$	(403.3)	$	(3.5)	$	(564.3)	$	(557.0)	$	(7.3)

Fairvalueinputsliabilitiesquantitativeinformationtabletextblock

	As of March 31, 2015							As of December 31, 2014
		Range					Period Covered		Range					Period Covered
Energy Prices:
ES, CL&P	$	48			per MWh		2020	$	52			per MWh		2020
Capacity Prices:
ES	$	8.80	-	12.98		per kW-Month	2016 - 2026	$	5.30	-	12.98		per kW-Month	2016 - 2026
CL&P	$	11.13	-	12.98		per kW-Month	2019 - 2026	$	11.08	-	12.98		per kW-Month	2018 - 2026
NSTAR Electric	$	8.80	-	11.13		per kW-Month	2016 - 2019	$	5.30	-	11.10		per kW-Month	2016 - 2019
Forward Reserve:
ES, CL&P	$	5.80	-	9.50		per kW-Month	2015 - 2024	$	5.80	-	9.50		per kW-Month	2015 - 2024
REC Prices:
ES, NSTAR Electric	$	45	-	50	per REC		2015 - 2018	$	38	-	56	per REC		2015 - 2018