ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)

ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)

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

	For the Nine Months Ended September 30, 2021								For the Nine Months Ended September 30, 2020
Eversource (Millions of Dollars)	Qualified Cash Flow Hedging Instruments		Unrealized Gains/(Losses) on Marketable Securities		Defined Benefit Plans		Total		Qualified Cash Flow Hedging Instruments		Unrealized Gains on Marketable Securities		Defined Benefit Plans		Total
Balance as of Beginning of Period	$	(1.4)	$	1.1	$	(76.1)	$	(76.4)	$	(3.0)	$	0.7	$	(62.8)	$	(65.1)
OCI Before Reclassifications	—		(0.6)		(2.4)		(3.0)		—		0.3		(1.6)		(1.3)
Amounts Reclassified from AOCI	1.0		—		6.5		7.5		1.2		—		4.8		6.0
Net OCI	1.0		(0.6)		4.1		4.5		1.2		0.3		3.2		4.7
Balance as of End of Period	$	(0.4)	$	0.5	$	(72.0)	$	(71.9)	$	(1.8)	$	1.0	$	(59.6)	$	(60.4)

Defined benefit plan OCI amounts before reclassifications relate to actuarial gains and losses that arose during the year and were recognized in AOCI. The unamortized actuarial gains and losses and prior service costs on the defined benefit plans are amortized from AOCI into Other Income, Net over the average future employee service period, and are reflected in amounts reclassified from AOCI.