FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

3 Months Ended

Mar. 31, 2021

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 March 31, 2021:
Preferred Stock Not Subject to Mandatory Redemption	$	155.6	$	168.3	$	116.2	$	123.2	$	43.0	$	45.1	$	—	$	—
Long-Term Debt	15,993.9		17,198.2		3,914.7		4,423.9		3,643.8		4,063.7		977.3		1,011.0
Rate Reduction Bonds	518.5		568.0		—		—		—		—		518.5		568.0
As of December 31, 2020:
Preferred Stock Not Subject to Mandatory Redemption	$	155.6	$	169.1	$	116.2	$	123.4	$	43.0	$	45.7	$	—	$	—
Long-Term Debt	16,179.1		18,420.1		3,914.8		4,800.9		3,643.2		4,294.0		1,099.1		1,207.0
Rate Reduction Bonds	540.1		603.4		—		—		—		—		540.1		603.4