Basis of Presentation (Tables)

12 Months Ended

Dec. 31, 2012

Notes To Consolidated Financial Statements [Abstract]

Schedule of Reclassification Adjustments [Table Text Block]

	Transmission Expense				Energy Efficiency Expense
	For the Years Ended December 31,				For the Years Ended December 31,
(Millions of Dollars)	2011		2010		2011		2010
NU	$	77.2	$	48.9	$	131.4	$	124.0
CL&P		52.6		39.4		90.3		92.3
PSNH		19.1		26.4		12.9		12.0
WMECO		15.9		18.3		21.8		16.3