FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

9 Months Ended

Sep. 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 September 30, 2019:
Preferred Stock Not Subject to Mandatory Redemption	$	155.6	$	160.3	$	116.2	$	116.6	$	43.0	$	43.7	$	—	$	—
Long-Term Debt	14,293.2		15,479.2		3,518.5		4,104.4		3,341.6		3,695.3		1,101.5		1,165.7
Rate Reduction Bonds	583.3		634.1		—		—		—		—		583.3		634.1
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