FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value, by Balance Sheet Grouping

Carrying amounts and estimated fair values are as follows:

	As of March 31, 2018				As of December 31, 2017
Eversource (Millions of Dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Preferred Stock Not Subject to Mandatory Redemption	$	155.6	$	165.8	$	155.6	$	160.8
Long-Term Debt	13,113.3		13,376.1		12,325.5		12,877.1

	CL&P				NSTAR Electric				PSNH
(Millions of Dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value		Carrying Amount		Fair Value
As of March 31, 2018:
Preferred Stock Not Subject to Mandatory Redemption	$	116.2	$	122.3	$	43.0	$	43.5	$	—	$	—
Long-Term Debt	3,553.6		3,821.9		2,943.9		3,071.7		1,001.8		1,025.2
As of December 31, 2017:
Preferred Stock Not Subject to Mandatory Redemption	$	116.2	$	116.5	$	43.0	$	44.3	$	—	$	—
Long-Term Debt	3,059.1		3,430.5		2,943.8		3,156.5		1,002.4		1,038.2