SHARE-BASED PAYMENTS (Tables)

12 Months Ended

Dec. 31, 2016

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Disclosure of Share-based Compensation Arrangements by Share-based Payment

The total compensation expense and associated future income tax benefits recognized by Eversource, CL&P, NSTAR Electric, PSNH and WMECO for share-based compensation awards were as follows:

Eversource	For the Years Ended December 31,
(Millions of Dollars)	2016		2015		2014
Compensation Expense	$	23.6	$	23.1	$	24.6
Future Income Tax Benefit	9.6		9.4		10.3

	For the Years Ended December 31,
	2016								2015								2014
(Millions of Dollars)	CL&P		NSTAR Electric		PSNH		WMECO		CL&P		NSTAR Electric		PSNH		WMECO		CL&P		NSTAR Electric		PSNH		WMECO
Compensation Expense	$	9.1	$	6.5	$	3.5	$	1.7	$	9.3	$	5.8	$	3.2	$	1.7	$	8.1	$	7.4	$	3.0	$	1.3
Future Income Tax Benefit	3.7		2.6		1.4		0.7		3.8		2.4		1.3		0.7		3.4		3.1		1.3		0.5

Restricted Stock Units (RSUs) [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of Share Transactions

A summary of RSU transactions is as follows:

	RSUs (Units)		Weighted Average Grant-Date Fair Value
Outstanding as of December 31, 2015	729,308		$	43.45
Granted	305,340		$	54.67
Shares Issued	(270,060	)	$	44.94
Forfeited	(40,318	)	$	53.99
Outstanding as of December 31, 2016	724,270		$	47.86

Performance Shares [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of Share Transactions

A summary of performance share transactions is as follows:

	Performance Shares (Units)		Weighted Average Grant-Date Fair Value
Outstanding as of December 31, 2015	528,428		$	46.30
Granted	222,139		$	53.64
Shares Issued	(201,826	)	$	40.93
Forfeited	(25,807	)	$	54.48
Outstanding as of December 31, 2016	522,934		$	51.09

Employee Stock Option [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of Share Transactions

 A summary of stock option transactions is as follows:

	Options		Weighted Average Exercise Price		Intrinsic Value (Millions)
Outstanding and Exercisable - December 31, 2015	171,872		$	26.47	$	4.2
Exercised	(47,232	)	$	28.12	$	1.3
Outstanding and Exercisable - December 31, 2016	124,640		$	25.84	$	3.7