Share-Based Payments (Tables)

12 Months Ended

Dec. 31, 2015

Notes To Consolidated Financial Statements [Abstract]

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]

			Weighted Average
	RSUs		Grant-Date
	(Units)		Fair Value
Outstanding as of December 31, 2014		1,380,747	$	35.67
Granted		266,230	$	54.57
Shares issued		(888,495)	$	33.94
Forfeited		(29,174)	$	46.68
Outstanding as of December 31, 2015		729,308	$	43.45

	Performance		Weighted Average
	Shares		Grant-Date
	(Units)		Fair Value
Outstanding as of December 31, 2014		375,644	$	42.20
Granted		172,543	$	55.04
Shares issued		(4,604)	$	42.23
Forfeited		(15,155)	$	45.33
Outstanding as of December 31, 2015		528,428	$	46.30

Eversource	For the Years Ended December 31,
(Millions of Dollars)	2015		2014		2013
Compensation Expense	$	23.1	$	24.6	$	27.0
Future Income Tax Benefit		9.4		10.3		10.7

	For the Years Ended December 31,
	2015								2014								2013
			NSTAR								NSTAR								NSTAR
(Millions of Dollars)	CL&P		Electric		PSNH		WMECO		CL&P		Electric		PSNH		WMECO		CL&P		Electric		PSNH		WMECO
Compensation Expense	$	9.3	$	5.8	$	3.2	$	1.7	$	8.1	$	7.4	$	3.0	$	1.3	$	6.8	$	7.5	$	2.3	$	1.3
Future Income Tax Benefit		3.8		2.4		1.3		0.7		3.4		3.1		1.3		0.5		2.7		3.0		0.9		0.5

		Weighted Average		Intrinsic Value
	Options	Exercise Price		(Millions)
Outstanding and Exercisable - December 31, 2014	351,616	$	26.69	$	9.4
Exercised	(179,744)	$	26.90	$	4.4
Outstanding and Exercisable - December 31, 2015	171,872	$	26.47	$	4.2