Pension Benefits and Postretirement Benefits Other Than Pensions (Tables)

9 Months Ended

Sep. 30, 2012

Notes To Consolidated Financial Statements [Abstract]

Schedule Of Net Benefit Costs [Table Text Block]

	Pension and SERP Plans
	For the Three Months Ended				For the Nine Months Ended
	September 30, 2012		September 30, 2011		September 30, 2012		September 30, 2011
(Millions of Dollars)	NU		NU		NU		NU
Service Cost	$	23.0	$	13.8	$	61.1	$	27.5
Interest Cost		53.3		38.3		144.7		76.5
Expected Return on Plan Assets		(59.5)		(42.7)		(161.3)		(85.8)
Actuarial Loss		47.4		21.1		125.0		42.1
Prior Service Cost		2.0		2.4		6.1		4.8
Total - Net Periodic Benefit Expense	$	66.2	$	32.9	$	175.6	$	65.1
Capitalized Pension Expense	$	19.2	$	7.8	$	49.5	$	23.5
	PBOP Plans and Group Welfare Benefit Plans
	For the Three Months Ended				For the Nine Months Ended
	September 30, 2012		September 30, 2011		September 30, 2012		September 30, 2011
(Millions of Dollars)	NU		NU		NU		NU
Service Cost	$	4.4	$	2.3	$	11.3	$	6.8
Interest Cost		14.3		6.4		34.4		19.3
Expected Return on Plan Assets		(11.1)		(5.4)		(28.1)		(16.2)
Actuarial Loss		10.3		4.8		25.5		14.3
Prior Service Credit		(0.5)		(0.1)		(0.9)		(0.2)
Net Transition Obligation Cost		3.1		2.9		9.0		8.7
Total - Net Periodic Benefit Expense	$	20.5	$	10.9	$	51.2	$	32.7

		Pension and SERP Plans
		For the Three Months Ended September 30, 2012								For the Three Months Ended September 30, 2011
				NSTAR								NSTAR
(Millions of Dollars)		CL&P		Electric (1)		PSNH		WMECO		CL&P		Electric(1), (2)		PSNH		WMECO
Service Cost		$	5.4	$	7.6	$	2.9	$	1.0	$	4.9	$	6.5	$	2.6	$	1.0
Interest Cost			12.9		14.7		6.1		2.6		13.0		15.2		6.1		2.7
Expected Return on Plan Assets			(17.7)		(16.4)		(7.2)		(4.1)		(19.1)		(17.8)		(5.0)		(4.4)
Actuarial Loss			12.6		15.7		4.2		2.7		8.2		12.2		2.6		1.7
Prior Service Cost/(Credit)			0.9		(0.1)		0.4		0.2		1.1		(0.2)		0.5		0.2
Total - Net Periodic Benefit Expense		$	14.1	$	21.5	$	6.4	$	2.4	$	8.1	$	15.9	$	6.8	$	1.2
Related Intercompany
	Allocations	$	10.7	$	(3.0)	$	2.4	$	2.1	$	8.5	$	(2.3)	$	1.9	$	1.6
Capitalized Pension Expense		$	6.8	$	8.4	$	1.9	$	1.3	$	4.5	$	4.9	$	2.1	$	0.7
		Pension and SERP Plans
		For the Nine Months Ended September 30, 2012								For the Nine Months Ended September 30, 2011
				NSTAR								NSTAR
(Millions of Dollars)		CL&P		Electric(1), (2)		PSNH		WMECO		CL&P		Electric(1), (2)		PSNH		WMECO
Service Cost		$	16.3	$	22.7	$	8.8	$	3.1	$	14.6	$	19.5	$	7.9	$	3.0
Interest Cost			38.5		44.2		18.3		7.9		39.1		45.7		18.4		8.1
Expected Return on Plan Assets			(52.8)		(49.2)		(21.1)		(12.3)		(57.4)		(53.5)		(15.0)		(13.2)
Actuarial Loss			37.0		47.3		12.1		8.0		24.8		36.5		7.8		5.1
Prior Service Cost/(Credit)			2.7		(0.4)		1.1		0.6		3.1		(0.6)		1.5		0.6
Total - Net Periodic Benefit Expense		$	41.7	$	64.6	$	19.2	$	7.3	$	24.2	$	47.6	$	20.6	$	3.6
Related Intercompany
	Allocations	$	32.0	$	(9.2)	$	7.5	$	6.0	$	25.0	$	(6.8)	$	5.7	$	4.6
Capitalized Pension Expense		$	20.2	$	23.6	$	5.8	$	3.7	$	13.4	$	14.7	$	5.9	$	2.1

		PBOP Plans
		For the Three Months Ended September 30, 2012						For the Three Months Ended September 30, 2011
(Millions of Dollars)		CL&P			PSNH		WMECO	CL&P		PSNH		WMECO
Service Cost		$	0.8	$	0.5	$	0.1	$	0.7	$	0.5	$	0.2
Interest Cost			2.3		1.1		0.5		2.5		1.2		0.5
Expected Return on Plan Assets			(2.3)		(1.1)		(0.5)		(2.2)		(1.1)		(0.5)
Actuarial Loss			1.9		0.9		0.3		1.9		0.8		0.3
Net Transition Obligation Cost			1.5		0.6		0.3		1.5		0.6		0.3
Total - Net Periodic Benefit Expense		$	4.2	$	2.0	$	0.7	$	4.4	$	2.0	$	0.8
Related Intercompany
	Allocations	$	2.0	$	0.5	$	0.4	$	2.0	$	0.5	$	0.4
		PBOP Plans
		For the Nine Months Ended September 30, 2012						For the Nine Months Ended September 30, 2011
(Millions of Dollars)		CL&P		PSNH		WMECO		CL&P		PSNH		WMECO
Service Cost		$	2.2	$	1.5	$	0.4	$	2.2	$	1.4	$	0.4
Interest Cost			6.9		3.4		1.5		7.5		3.6		1.6
Expected Return on Plan Assets			(6.8)		(3.4)		(1.6)		(6.5)		(3.3)		(1.5)
Actuarial Loss			5.7		2.7		0.9		5.4		2.4		0.9
Net Transition Obligation Cost			4.6		1.9		1.1		4.6		1.9		1.0
Total - Net Periodic Benefit Expense		$	12.6	$	6.1	$	2.3	$	13.2	$	6.0	$	2.4
Related Intercompany
	Allocations	$	5.9	$	1.5	$	1.1	$	6.2	$	1.5	$	1.1