ASSET RETIREMENT OBLIGATIONS (Tables)

12 Months Ended

Dec. 31, 2025

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Change in Asset Retirement Obligation

A reconciliation of the beginning and ending carrying amounts of ARO liabilities is as follows:

	As of December 31,
	2025								2024
(Millions of Dollars)	Eversource		CL&P		NSTAR Electric		PSNH		Eversource		CL&P		NSTAR Electric		PSNH
Balance as of Beginning of Year	$	590.9	$	42.5	$	109.3	$	5.6	$	505.8	$	39.9	$	104.8	$	5.2
Liabilities Settled During the Year	(24.2)		—		—		—		(24.6)		—		—		—
Accretion	34.0		2.9		4.7		0.3		29.5		2.6		4.5		0.4
Revisions in Estimated Cash Flows	(5.3)		—		—		—		80.2		—		—		—
Balance as of End of Year	$	595.4	$	45.4	$	114.0	$	5.9	$	590.9	$	42.5	$	109.3	$	5.6