QUARTERLY FINANCIAL DATA (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2011

Quarterly Financial Data [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

NU Consolidated Statements of Quarterly Financial Data	Quarter Ended (a)
(Millions of Dollars, except per share information)	March 31,		June 30,		September 30,			December 31,
2011
Operating Revenues	$	1,235.3	$	1,047.5	$	1,114.9		$	1,068.0
Operating Income		227.4		178.1		203.8			184.9
Net Income		115.6		78.7		91.4			114.8
Net Income Attributable to Controlling Interests		114.2		77.3		90.0			113.2
Basic and Diluted Earnings Per Common Share	$	0.64	$	0.44	$	0.51		$	0.64
2010
Operating Revenues	$	1,339.4	$	1,111.4	$	1,243.3		$	1,204.1
Operating Income		226.7		178.3		199.6			195.3
Net Income		87.6		73.3		101.9			131.3
Net Income Attributable to Controlling Interests		86.2		71.9		100.5			129.3
Basic and Diluted Earnings Per Common Share	$	0.49	$	0.41	$	0.57		$	0.73
(a) The summation of quarterly EPS data may not equal annual data due to rounding.
CL&P Consolidated Statements of Quarterly Financial Data	Quarter Ended
(Millions of Dollars)	March 31,		June 30,		September 30,			December 31,
2011
Operating Revenues	$	673.7	$	608.0	$	673.7		$	593.0
Operating Income		126.0		114.8		137.7			84.7
Net Income		64.3		52.6		66.5			66.8
2010
Operating Revenues	$	795.0	$	707.9	$	789.2		$	707.0
Operating Income		125.5		106.2		131.4			124.6
Net Income		48.4		44.1		69.0			82.6
PSNH Consolidated Statements of Quarterly Financial Data	Quarter Ended
(Millions of Dollars)	March 31,		June 30,		September 30,			December 31,
2011
Operating Revenues	$	269.5	$	240.2	$	259.6		$	243.7
Operating Income		46.9		37.9		48.5			46.8
Net Income		27.5		21.7		25.6			25.5
2010
Operating Revenues	$	258.6	$	238.3	$	277.0		$	259.5
Operating Income		39.9		43.4		49.8			43.1
Net Income		15.8		21.6		28.8			23.9
WMECO Consolidated Statements of Quarterly Financial Data	Quarter Ended
(Millions of Dollars)	March 31,		June 30,		September 30,			December 31,
2011
Operating Revenues	$	106.7	$	98.4	$	104.5		$	107.7
Operating Income		21.1		18.5		19.8			29.0
Net Income		10.0		8.2		8.4	(1)		16.5
2010
Operating Revenues	$	100.2	$	92.5	$	103.7		$	98.8
Operating Income		16.4		14.3		14.9			13.1
Net Income		5.7		5.2		7.3			4.9