ASSET RETIREMENT OBLIGATIONS (TABLE)

12 Months Ended

Dec. 31, 2012

Notes To Consolidated Financial Statements [Abstract]

Schedule of Change in Asset Retirement Obligation [Table Text Block]

NU			As of December 31,
(Millions of Dollars)			2012		2011
Balance as of Beginning of Year			$	56.2	$	53.3
Liability Assumed Upon Consolidation of CYAPC and YAEC				284.2		-
Liability Assumed Upon Merger With NSTAR				35.9		-
Liabilities Incurred During the Year				1.5		2.1
Liabilities Settled During the Year				(7.2)		(0.8)
Accretion				20.2		3.5
Revisions in Estimated Cash Flows				21.4		(1.9)
Balance as of End of Year			$	412.2	$	56.2
	As of December 31,
	2012								2011
			NSTAR								NSTAR
(Millions of Dollars)	CL&P		Electric		PSNH		WMECO		CL&P		Electric(1)		PSNH		WMECO
Balance as of Beginning of Year	$	32.2	$	27.5	$	17.0	$	4.0	$	29.3	$	26.2	$	17.6	$	3.6
Liabilities Incurred During the Year		-		-		0.3		-		1.7		-		0.2		0.2
Liabilities Settled During the Year		(0.9)		(1.0)		-		-		(0.8)		-		-		-
Accretion		2.0		1.5		1.1		0.3		2.0		1.3		1.1		0.2
Revisions in Estimated Cash Flows		0.3		3.4		-		-		-		-		(1.9)		-
Balance as of End of Year	$	33.6	$	31.4	$	18.4	$	4.3	$	32.2	$	27.5	$	17.0	$	4.0
(1)NSTAR Electric amounts are not included in NU consolidated as of December 31, 2011.