FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

6 Months Ended

Jun. 30, 2019

Fair Value Disclosures [Abstract]

Carrying Amounts and Estimated Fair Values of Financial Instruments

Carrying amounts and estimated fair values are as follows:

	Eversource				CL&P				NSTAR Electric				PSNH
(Millions of Dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value		Carrying Amount		Fair Value		Carrying Amount		Fair Value
As of June 30, 2019:
Preferred Stock Not Subject to Mandatory Redemption	$	155.6	$	161.0	$	116.2	$	117.4	$	43.0	$	43.6	$	—	$	—
Long-Term Debt	13,818.5		14,639.4		3,309.5		3,724.9		3,341.5		3,599.6		1,101.8		1,145.3
Rate Reduction Bonds	604.9		642.2		—		—		—		—		604.9		642.2
As of December 31, 2018:
Preferred Stock Not Subject to Mandatory Redemption	$	155.6	$	156.8	$	116.2	$	113.8	$	43.0	$	43.0	$	—	$	—
Long-Term Debt	13,086.1		13,154.9		3,254.0		3,429.2		2,944.8		3,024.1		805.2		819.5
Rate Reduction Bonds	635.7		645.8		—		—		—		—		635.7		645.8