QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Data [Abstract]

Schedule of Quarterly Financial Information

	Quarter Ended
Eversource (Millions of Dollars, except   per share information)	2017								2016
	March 31,		June 30,		September 30,		December 31,		March 31,		June 30,		September 30,		December 31,
Operating Revenues	$	2,105.1	$	1,762.8	$	1,988.5	$	1,895.6	$	2,055.6	$	1,767.2	$	2,039.7	$	1,776.6
Operating Income	509.0		455.7		502.6		450.9		488.5		423.4		509.9		438.1
Net Income	261.3		232.6		262.2		239.4		246.0		205.5		267.2		231.1
Net Income Attributable   to Common Shareholders	259.5		230.7		260.4		237.4		244.2		203.6		265.3		229.2
Basic EPS (1)	$	0.82	$	0.73	$	0.82	$	0.75	$	0.77	$	0.64	$	0.83	$	0.72
Diluted EPS (1)	$	0.82	$	0.73	$	0.82	$	0.75	$	0.77	$	0.64	$	0.83	$	0.72

(1)    The summation of quarterly EPS data may not equal annual data due to rounding.

	Quarter Ended
	2017								2016
(Millions of Dollars)	March 31,		June 30,		September 30,		December 31,		March 31,		June 30,		September 30,		December 31,
CL&P
Operating Revenues	$	732.3	$	666.6	$	774.8	$	713.7	$	735.3	$	679.8	$	760.0	$	630.9
Operating Income	176.0		176.0		177.5		155.6		171.5		162.1		176.1		163.5
Net Income	90.2		91.3		96.1		99.1		87.0		82.9		86.6		77.8
NSTAR Electric
Operating Revenues	$	733.8	$	704.7	$	851.9	$	690.2	$	742.2	$	707.6	$	904.4	$	687.4
Operating Income	161.6		182.7		234.4		128.9		142.9		159.7		240.8		130.8
Net Income	83.4		95.0		125.8		70.5		71.3		81.4		133.2		64.9
PSNH
Operating Revenues	$	253.2	$	230.4	$	250.0	$	248.0	$	242.3	$	218.5	$	266.9	$	231.8
Operating Income	68.3		64.9		67.4		71.2		70.7		63.1		74.7		54.6
Net Income	34.3		31.6		33.7		36.4		36.1		31.3		38.5		26.1