Presentation (Tables)

6 Months Ended

Jun. 30, 2012

Notes To Consolidated Financial Statements [Abstract]

ScheduleOfReclassificationAdjustments

	Transmission Expense				Energy Efficiency Expense
	Three Months Ended		Six Months Ended		Three Months Ended		Six Months Ended
(Millions of Dollars)	June 30, 2011		June 30, 2011		June 30, 2011		June 30, 2011
NU	$	42.2	$	64.8	$	30.0	$	64.4
CL&P		23.2		39.8		21.3		44.7
PSNH		5.0		12.9		2.8		5.8
WMECO		5.3		10.4		5.0		10.4