LEASES (Tables)

12 Months Ended

Dec. 31, 2012

Notes To Consolidated Financial Statements [Abstract]

Schedule of Rent Expense [Table Text Block]

					NSTAR
(Millions of Dollars)	NU		CL&P		Electric (1)		PSNH		WMECO
2012	$	14.8	$	8.2	$	6.2	$	2.5	$	3.0
2011		8.4		8.3		19.8		2.1		2.8
2010		11.9		10.0		19.2		2.2		2.8

Schedule of Future Minimum Lease Payments for Capital Leases [Table Text Block]

Capital Leases
(Millions of Dollars)	NU		CL&P		PSNH
2013	$	2.8	$	2.2	$	0.5
2014		2.2		2.0		0.2
2015		2.2		2.0		0.2
2016		2.0		1.9		0.1
2017		2.0		2.0		0.0
Thereafter		7.5		7.3		0.0
Future minimum lease payments		18.7		17.4		1.0
Less amount representing interest		7.6		7.4		0.1
Present value of future minimum lease payments	$	11.1	$	10.0	$	0.9

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]

Operating Leases
(Millions of Dollars)	NU		CL&P		NSTAR Electric		PSNH		WMECO
2013	$	22.4	$	4.3	$	10.9	$	1.3	$	2.7
2014		16.6		3.7		8.2		1.0		1.1
2015		14.1		3.1		7.4		0.8		0.6
2016		11.2		2.3		6.1		0.6		0.3
2017		8.6		1.2		5.1		0.5		0.2
Thereafter		23.3		6.4		10.3		1.8		1.2
Future minimum lease payments	$	96.2	$	21.0	$	48.0	$	6.0	$	6.1