FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

6 Months Ended

Jun. 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 June 30, 2021:
Preferred Stock Not Subject to Mandatory Redemption	$	155.6	$	166.4	$	116.2	$	122.2	$	43.0	$	44.2	$	—	$	—
Long-Term Debt	16,651.2		18,364.0		4,335.6		5,049.8		3,688.3		4,208.4		1,163.7		1,239.0
Rate Reduction Bonds	518.5		579.6		—		—		—		—		518.5		579.6
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