FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

6 Months Ended

Jun. 30, 2017

Fair Value Disclosures [Abstract]

Fair Value, by Balance Sheet Grouping

Carrying amounts and estimated fair values are as follows:

	As of June 30, 2017				As of December 31, 2016
Eversource (Millions of Dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Preferred Stock Not Subject to Mandatory Redemption	$	155.6	$	158.4	$	155.6	$	158.3
Long-Term Debt	10,382.9		10,935.8		9,603.2		9,980.5

	CL&P				NSTAR Electric				PSNH				WMECO
(Millions of Dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value		Carrying Amount		Fair Value		Carrying Amount		Fair Value
As of June 30, 2017:
Preferred Stock Not Subject to Mandatory Redemption	$	116.2	$	115.0	$	43.0	$	43.4	$	—	$	—	$	—	$	—
Long-Term Debt	2,913.5		3,247.3		2,425.9		2,605.9		1,072.3		1,122.3		566.3		602.8
As of December 31, 2016:
Preferred Stock Not Subject to Mandatory Redemption	$	116.2	$	114.7	$	43.0	$	43.6	$	—	$	—	$	—	$	—
Long-Term Debt	2,766.0		3,049.6		2,078.1		2,201.6		1,072.0		1,109.7		566.5		589.0