QUARTERLY FINANCIAL DATA (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2014

Quarterly Financial Data [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

NU Consolidated Statements of Quarterly Financial Data	Quarter Ended
(Millions of Dollars, except per share information)	March 31,		June 30,		September 30,		December 31,
2014
Operating Revenues	$	2,290.6	$	1,677.6	$	1,892.5	$	1,881.2
Operating Income		467.7		294.0		440.9		430.2
Net Income		237.8		129.2		236.5		223.6
Net Income Attributable to Controlling Interest		236.0		127.4		234.6		221.5
Basic EPS (a)	$	0.75	$	0.40	$	0.74	$	0.69
Diluted EPS (a)	$	0.74	$	0.40	$	0.74	$	0.69
2013
Operating Revenues	$	1,995.0	$	1,635.9	$	1,892.6	$	1,777.7
Operating Income		418.9		350.6		399.3		360.6
Net Income		230.0		173.1		211.4		179.2
Net Income Attributable to Controlling Interest		228.1		171.0		209.5		177.4
Basic and Diluted EPS (a)	$	0.72	$	0.54	$	0.66	$	0.56
(a) The summation of quarterly EPS data may not equal annual data due to rounding.
Statements of Quarterly Financial Data	Quarter Ended
(Millions of Dollars)	March 31,		June 30,		September 30,		December 31,
CL&P
2014
Operating Revenues	$	734.6	$	587.3	$	695.6	$	675.1
Operating Income		158.0		92.1		146.2		159.0
Net Income		79.3		37.4		83.9		87.2
2013
Operating Revenues	$	624.1	$	569.3	$	648.4	$	600.5
Operating Income		149.7		136.8		133.9		119.2
Net Income		85.0		67.9		66.3		60.2
NSTAR Electric
2014
Operating Revenues	$	666.2	$	561.5	$	727.9	$	581.1
Operating Income		118.4		121.5		206.6		132.0
Net Income		58.1		60.1		115.6		69.3
2013
Operating Revenues	$	592.3	$	570.4	$	753.9	$	576.9
Operating Income		94.5		112.5		192.0		109.2
Net Income		48.1		58.0		107.0		55.4
PSNH
2014
Operating Revenues	$	299.8	$	211.6	$	223.7	$	224.4
Operating Income		64.0		49.0		56.4		60.0
Net Income		32.6		24.1		28.2		29.0
2013
Operating Revenues	$	273.8	$	216.1	$	218.6	$	226.9
Operating Income		58.1		54.3		56.6		56.2
Net Income		29.0		27.2		28.4		26.8
WMECO
2014
Operating Revenues	$	137.4	$	108.3	$	118.1	$	129.6
Operating Income		34.7		17.7		31.2		34.0
Net Income		18.1		7.0		14.7		18.0
2013
Operating Revenues	$	125.0	$	115.0	$	121.8	$	110.9
Operating Income		35.6		32.4		28.9		22.4
Net Income		18.6		16.4		15.0		10.4