ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Tables)

3 Months Ended

Mar. 31, 2024

Equity [Abstract]

Changes in Accumulated Other Comprehensive Income/(Loss) by Component, Net of Tax

The changes in accumulated other comprehensive income/(loss) by component, net of tax, are as follows:

	For the Three Months Ended March 31, 2024						For the Three Months Ended March 31, 2023
Eversource (Millions of Dollars)	Qualified Cash Flow Hedging Instruments		Defined Benefit Plans		Total		Qualified Cash Flow Hedging Instruments		Unrealized Gains/(Losses) on Marketable Securities		Defined Benefit Plans		Total
Balance as of Beginning of Period	$	(0.4)	$	(33.3)	$	(33.7)	$	(0.4)	$	(1.2)	$	(37.8)	$	(39.4)
Amounts Reclassified from AOCI	—		5.2		5.2		—		1.2		2.0		3.2
Net OCI	—		5.2		5.2		—		1.2		2.0		3.2
Balance as of End of Period	$	(0.4)	$	(28.1)	$	(28.5)	$	(0.4)	$	—	$	(35.8)	$	(36.2)