Pension and Other Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2020

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Allocation of Plan Assets

Asset Mix Policy of Funds:

	Defined Benefit Pension Plan		Postretirement Benefit Plan
Asset Category	Minimum	Maximum	Minimum	Maximum
Domestic Equities	12%	32%	0%	55%
International Equities	6%	16%	0%	25%
Fixed Income	59%	71%	20%	100%
Real Estate	0%	7%	0%	0%
Private Equity	0%	5%	0%	0%
Short-Term Investments	0%	10%	0%	10%

As of December 31, 2019, the asset mix and acceptable minimum and maximum ranges established by the policy for the pension and other postretirement benefit plans were as follows:

Asset Mix Policy of Funds:

	Defined Benefit Pension Plan		Postretirement Benefit Plan
Asset Category	Minimum	Maximum	Minimum	Maximum
Domestic Equities	12%	32%	0%	55%
International Equities	6%	16%	0%	25%
Fixed Income	59%	71%	20%	100%
Real Estate	0%	7%	0%	0%
Private Equity	0%	5%	0%	0%
Short-Term Investments	0%	10%	0%	10%

Pension Plan and Postretirement Plan Asset Mix at December 31, 2020 and December 31, 2019:

	Defined Benefit Pension Assets		December 31, 2020		Postretirement Benefit Plan Assets		December 31, 2020
Asset Class (in millions)	Asset Value		% of Total Assets		Asset Value		% of Total Assets
Domestic Equities	$	446.3	21.0	%	$	108.8	38.0	%
International Equities	230.1		10.9	%	48.2		16.8	%
Fixed Income	1,291.2		61.0	%	122.0		42.6	%
Real Estate	52.9		2.5	%	—		—
Cash/Other	97.2		4.6	%	7.4		2.6	%
Total	$	2,117.7	100.0	%	$	286.4	100.0	%
	Defined Benefit Pension Assets		December 31, 2019		Postretirement Benefit Plan Assets		December 31, 2019
Asset Class (in millions)	Asset Value		% of Total Assets		Asset Value		% of Total Assets
Domestic Equities	$	446.4	21.5	%	$	93.8	35.9	%
International Equities	205.0		9.9	%	40.7		15.6	%
Fixed Income	1,337.2		64.2	%	119.5		45.7	%
Real Estate	53.9		2.6	%	—		—
Cash/Other	38.4		1.8	%	7.4		2.8	%
Total	$	2,080.9	100.0	%	$	261.4	100.0	%

Schedule Of Fair Value and Changes In The Fair Value Of The Plan Assets

Fair Value Measurements at December 31, 2020: 

(in millions)	December 31, 2020		Quoted Prices in  Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs  (Level 3)
Pension plan assets:
Cash	$	11.9	$	11.9	$	—	$	—
Equity securities
U.S. equities	2.4		2.4		—		—
Fixed income securities
Government	243.4		—		243.4		—
Corporate	692.6		—		692.6		—
Mutual Funds
U.S. multi-strategy	161.3		161.3		—		—
International equities	55.4		55.4		—		—
Fixed income	0.1		0.1		—		—
Private equity limited partnerships(3)
U.S. multi-strategy(1)	10.9		—		—		—
International multi-strategy(2)	6.6		—		—		—
Distressed opportunities	0.3		—		—		—
Real estate	52.9		—		—		—
Commingled funds(3)
Short-term money markets	78.8		—		—		—
U.S. equities	279.7		—		—		—
International equities	176.8		—		—		—
Fixed income	337.6		—		—		—
Pension plan assets subtotal	2,110.7		231.1		936.0		—
Other postretirement benefit plan assets:
Mutual funds
U.S. multi-strategy	94.8		94.8		—		—
International equities	24.1		24.1		—		—
Fixed income	121.8		121.8		—		—
Commingled funds(3)
Short-term money markets	7.6		—		—		—
U.S. equities	14.0		—		—		—
International equities	24.1		—		—		—
Other postretirement benefit plan assets subtotal	286.4		240.7		—		—
Due to brokers, net(4)	(1.6)		—		(1.6)		—
Accrued income/dividends	8.6		8.6		—		—
Total pension and other postretirement benefit plan assets	$	2,404.1	$	480.4	$	934.4	$	—

(1)This class includes limited partnerships/fund of funds that invest in a diverse portfolio of private equity strategies, including buy-outs, venture capital, growth capital, special situations and secondary markets, primarily inside the United States. 

(2)This class includes limited partnerships/fund of funds that invest in diverse portfolio of private equity strategies, including buy-outs, venture capital, growth capital, special situations and secondary markets, primarily outside the United States.

(3)This class of investments is measured at fair value using the net asset value per share and has not been classified in the fair value hierarchy.

(4)This class represents pending trades with brokers.

The table below sets forth a summary of unfunded commitments, redemption frequency and redemption notice periods for certain investments that are measured at fair value using the net asset value per share for the year ended December 31, 2020:

(in millions)	Fair Value		Redemption Frequency	Redemption Notice Period
Commingled Funds
Short-term money markets	$	86.4	Daily	1 day
U.S. equities	293.7		Daily	1-5 days
International equities	200.9		Monthly	10-30 days
Fixed income	337.6		Daily	3 days
Total	$	918.6

Fair Value Measurements at December 31, 2019: 

(in millions)	December 31, 2019		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs  (Level 3)
Pension plan assets:
Cash	$	6.7	$	6.7	$	—	$	—
Fixed income securities
Government	319.6		—		319.6		—
Corporate	651.8		—		651.8		—
Mutual Funds
U.S. multi-strategy	140.5		140.5		—		—
International equities	56.9		56.9		—		—
Private equity limited partnerships(3)
U.S. multi-strategy(1)	14.0		—		—		—
International multi-strategy(2)	8.5		—		—		—
Distressed opportunities	0.5		—		—		—
Real Estate	53.9		—		—		—
Commingled funds(3)
Short-term money markets	14.8		—		—		—
U.S. equities	305.9		—		—		—
International equities	148.1		—		—		—
Fixed income	351.8		—		—		—
Pension plan assets subtotal	2,073.0		204.1		971.4		—
Other postretirement benefit plan assets:
Mutual funds
U.S. multi-strategy	81.7		81.7		—		—
International equities	20.6		20.6		—		—
Fixed income	119.2		119.2		—		—
Commingled funds(3)
Short-term money markets	7.7		—		—		—
U.S. equities	12.1		—		—		—
International equities	20.1		—		—		—
Other postretirement benefit plan assets subtotal	261.4		221.5		—		—
Due to brokers, net(4)	(2.8)		—		(2.8)		—
Accrued income/dividends	10.7		10.7		—		—
Total pension and other postretirement benefit plan assets	$	2,342.3	$	436.3	$	968.6	$	—

(1)This class includes limited partnerships/fund of funds that invest in a diverse portfolio of private equity strategies, including buy-outs, venture capital, growth capital, special situations and secondary markets, primarily inside the United States. 

(2)This class includes limited partnerships/fund of funds that invest in diverse portfolio of private equity strategies, including buy-outs, venture capital, growth capital, special situations and secondary markets, primarily outside the United States.

(3)This class of investments is measured at fair value using the net asset value per share and has not been classified in the fair value hierarchy.

(4)This class represents pending trades with brokers.

The table below sets forth a summary of changes in the fair value of the Plan’s Level 3 assets for the year ended December 31, 2019:

	Balance at January 1, 2019		Transfers out (Level 3)(1)		Balance at December 31, 2019
Private equity limited partnerships
U.S. multi-strategy	18.5		(18.5)		—
International multi-strategy	12.5		(12.5)		—
Distress opportunities	2.4		(2.4)		—
Real estate	52.7		(52.7)		—
Total	$	86.1	$	(86.1)	$	—

(1)Level 3 assets from 2018 were reclassified in the 2019 presentation and included within the fair value hierarchy table as of December 31, 2019 as "Not Classified" investments for which fair value is measured using net asset value per share, consistent with the definitions described above.

The table below sets forth a summary of unfunded commitments, redemption frequency and redemption notice periods for certain investments that are measured at fair value using the net asset value per share for the year ended December 31, 2019:

(in millions)	Fair Value		Redemption Frequency	Redemption Notice Period
Commingled Funds
Short-term money markets	$	22.5	Daily	1 day
U.S. equities	318.0		Monthly	3 days
International equities	168.2		Monthly	10-30 days
Fixed income	351.8		Daily	3 days
Total	$	860.5

Schedule Of Reconciliation Of The Plan Funded Status

The following table provides a reconciliation of the plans’ funded status and amounts reflected in our Consolidated Balance Sheets at December 31 based on a December 31 measurement date:

	Pension Benefits				Other Postretirement Benefits
(in millions)	2020		2019		2020		2019
Change in projected benefit obligation(1)
Benefit obligation at beginning of year	$	2,130.5	$	1,981.3	$	576.5	$	492.5
Service cost	32.0		29.2		6.6		5.1
Interest cost	51.6		72.3		15.4		19.2
Plan participants’ contributions	—		—		4.1		4.8
Plan amendments	—		—		—		5.1
Actuarial loss(2)	140.1		204.3		24.8		88.8
Benefits paid	(174.5)		(156.6)		(37.0)		(39.5)
Estimated benefits paid by incurred subsidy	—		—		0.4		0.5
Spinoff to Eversource	(121.3)		—		—		—
Projected benefit obligation at end of year	$	2,058.4	$	2,130.5	$	590.8	$	576.5
Change in plan assets
Fair value of plan assets at beginning of year	$	2,080.9	$	1,867.7	$	261.4	$	216.3
Actual return on plan assets	329.9		366.8		36.3		56.9
Employer contributions	2.9		2.9		21.6		23.0
Plan participants’ contributions	—		—		4.1		4.7
Benefits paid	(174.6)		(156.5)		(37.0)		(39.5)
Spinoff to Eversource	(121.4)		—		—		—
Fair value of plan assets at end of year	$	2,117.7	$	2,080.9	$	286.4	$	261.4
Funded Status at end of year	$	59.3	$	(49.6)	$	(304.4)	$	(315.1)
Amounts recognized in the statement of financial position consist of:
Noncurrent assets	91.4		8.2		—		—
Current liabilities	(2.9)		(3.0)		(0.9)		(0.8)
Noncurrent liabilities	(29.2)		(54.8)		(303.5)		(314.3)
Net amount recognized at end of year(3)	$	59.3	$	(49.6)	$	(304.4)	$	(315.1)
Amounts recognized in accumulated other comprehensive income or regulatory asset/liability(4)
Unrecognized prior service credit	$	0.3	$	3.0	$	(10.1)	$	(10.7)
Unrecognized actuarial loss	497.2		652.8		116.4		118.4
Net amount recognized at end of year	$	497.5	$	655.8	$	106.3	$	107.7

(1)The change in benefit obligation for Pension Benefits represents the change in Projected Benefit Obligation while the change in benefit obligation for Other Postretirement Benefits represents the change in accumulated postretirement benefit obligation.

(2)The pension actuarial loss was primarily driven by the decrease in the discount rate, offset by the change in mortality assumptions. The other postretirement benefits loss was also primarily driven by a decrease in discount rates, offset by favorable claims experienced and a change in the mortality assumptions.

(3)We recognize our Consolidated Balance Sheets underfunded and overfunded status of our various defined benefit postretirement plans, measured as the difference between the fair value of the plan assets and the benefit obligation.

(3)We determined that for certain rate-regulated subsidiaries the future recovery of pension and other postretirement benefits costs is probable. These rate-regulated subsidiaries recorded regulatory assets and liabilities of $583.3 million and zero, respectively, as of December 31, 2020, and $739.1 million and $0.1 million, respectively, as of December 31, 2019 that would otherwise have been recorded to accumulated other comprehensive loss.

Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets

Information for pension plans with a projected benefit obligation in excess of plan assets:

	December 31,
	2020(1)		2019
Accumulated Benefit Obligation	$	32.1	$	1,473.9
Funded Status
Projected Benefit Obligation	32.1		1,492.9
Fair Value of Plan Assets	—		1,435.1
Funded Status of Underfunded Pension Plans at End of Year	$	(32.1)	$	(57.8)

(1)As of December 31, 2020, only our nonqualified plans were underfunded. These plans have no assets as they are not funded until benefits are paid.

Information for pension plans with plan assets in excess of the projected benefit obligation:

	December 31,
	2020		2019
Accumulated Benefit Obligation	$	2,004.7	$	637.6
Funded Status
Projected Benefit Obligation	2,026.3		637.6
Fair Value of Plan Assets	2,117.7		645.8
Funded Status of Overfunded Pension Plans at End of Year	$	91.4	$	8.2

Schedule Of Significant Actuarial Assumptions In Determining Funded Status Plan

The following table provides the key assumptions that were used to calculate the pension and other postretirement benefits obligations for our various plans as of December 31:

	Pension Benefits				Other Postretirement  Benefits
	2020		2019		2020		2019
Weighted-average assumptions to Determine Benefit Obligation
Discount Rate	2.38	%	3.12	%	2.49	%	3.21	%
Rate of Compensation Increases	4.00	%	4.00	%	—		—
Interest Crediting Rates	4.00	%	4.00	%	—		—
Health Care Trend Rates
Trend for Next Year	—		—		6.69	%	6.68	%
Ultimate Trend	—		—		4.50	%	4.50	%
Year Ultimate Trend Reached	—		—		2029		2028

The following table provides the key assumptions that were used to calculate the net periodic benefits cost for our various plans:

	Pension Benefits						Other Postretirement Benefits
	2020		2019		2018		2020		2019		2018
Weighted-average Assumptions to Determine Net Periodic Benefit Cost
Discount rate - service cost	3.39	%	4.48	%	3.79	%	3.52	%	4.59	%	3.89	%
Discount rate - interest cost	2.65	%	3.84	%	3.15	%	2.76	%	3.94	%	3.27	%
Expected Long-Term Rate of Return on Plan Assets	5.70	%	6.10	%	7.00	%	5.67	%	5.83	%	5.80	%
Rate of Compensation Increases	4.00	%	4.00	%	4.00	%	—		—		—
Interest Crediting Rates	4.00	%	4.00	%	4.00	%	—		—		—

Schedule Of Expected Payments To Participants In Pension Plan

The expected benefits are estimated based on the same assumptions used to measure our benefit obligation at the end of the year and include benefits attributable to the estimated future service of employees:

(in millions)	Pension Benefits		Other Postretirement Benefits		Federal Subsidy Receipts
Year(s)
2021	$	218.8	$	38.4	$	0.4
2022	154.5		37.8		0.4
2023	149.2		37.3		0.4
2024	145.9		37.0		0.4
2025	141.3		36.6		0.3
2026-2030	621.9		172.1		1.2

Components Of The Plans' Net Periodic Benefits Cost

The following table provides the components of the plans’ actuarially determined net periodic benefits cost for each of the three years ended December 31, 2020, 2019 and 2018:

	Pension Benefits						Other Postretirement Benefits
(in millions)	2020		2019		2018		2020		2019		2018
Components of Net Periodic Benefit Cost(1)
Service cost	$	32.0	$	29.2	$	31.3	$	6.6	$	5.1	$	5.0
Interest cost	51.6		72.3		67.1		15.4		19.2		17.6
Expected return on assets	(111.6)		(108.8)		(142.3)		(14.4)		(13.1)		(14.9)
Amortization of prior service cost (credit)	0.7		0.2		(0.4)		(2.1)		(3.2)		(4.0)
Recognized actuarial loss	33.8		45.2		40.6		4.9		2.0		3.8
Settlement/curtailment loss	10.5		9.5		18.5		1.5		—		—
Total Net Periodic Benefits Cost	$	17.0	$	47.6	$	14.8	$	11.9	$	10.0	$	7.5

(1)Service cost is presented in "Operation and maintenance" on the Statements of Consolidated Income (Loss). Non-service cost components are presented within "Other, net."

Schedule Of Changes In Plan Assets And Projected Benefit Obligations Recognized In Other Comprehensive Income

The following table provides other changes in plan assets and projected benefit obligations recognized in other comprehensive income or regulatory asset or liability:

	Pension Benefits				Other Postretirement Benefits
(in millions)	2020		2019		2020		2019
Other Changes in Plan Assets and Projected Benefit Obligations Recognized in Other Comprehensive Income or Regulatory Asset or Liability
Net prior service cost	$	—	$	—	$	—	$	5.1
Net actuarial loss (gain)	(78.2)		(53.8)		2.9		45.1
Settlements/curtailments	(10.5)		(9.5)		(1.5)		—
Less: amortization of prior service cost	(0.7)		(0.2)		2.1		3.2
Less: amortization of net actuarial loss	(33.8)		(45.2)		(4.9)		(2.0)
Less: gain attributable to spinoff to Eversource	(33.1)		—		—		—
Less: prior service cost attributable to spinoff to Eversource	(2.0)		—		—		—
Total Recognized in Other Comprehensive Income or Regulatory Asset or  Liability	$	(158.3)	$	(108.7)	$	(1.4)	$	51.4
Amount Recognized in Net Periodic Benefits Cost and Other Comprehensive Income or Regulatory Asset or Liability	$	(141.3)	$	(61.1)	$	10.5	$	61.4