FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

9 Months Ended

Sep. 30, 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 September 30, 2021:
Preferred Stock Not Subject to Mandatory Redemption	$	155.6	$	165.5	$	116.2	$	121.4	$	43.0	$	44.1	$	—	$	—
Long-Term Debt	18,219.2		19,810.9		4,215.1		4,865.2		3,984.7		4,494.3		1,163.6		1,228.9
Rate Reduction Bonds	496.9		555.8		—		—		—		—		496.9		555.8
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