Equity Method Investments (Tables)

12 Months Ended

Dec. 31, 2012

Notes To Consolidated Financial Statements [Abstract]

Schedule of Equity Method Investments [Table Text Block]

(Percent)	CYAPC	YAEC	MYAPC
CL&P	34.5	24.5	12.0
NSTAR Electric	14.0	14.0	4.0
PSNH	5.0	7.0	5.0
WMECO	9.5	7.0	3.0

	As of December 31,
(Millions of Dollars)	2012		2011 (1)
CL&P	$	1.4	$	1.4
NSTAR Electric		0.6		0.6
PSNH		0.3		0.3
WMECO		0.4		0.4