Benefit Plans and Other Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2021

Benefit Plans and Other Postretirement Benefits [Abstract]

Target Asset Allocations and Plan Assets Measured at Fair Value

, PSCo’s pension plan assets measured at fair value:

	Dec. 31, 2021 (a)										Dec. 31, 2020 (a)
(Millions of Dollars)	Level 1		Level 2		Level 3		Measured at NAV		Total		Level 1		Level 2		Level 3		Measured at NAV		Total
Cash equivalents	$	49	$	—	$	—	$	—	$	49	$	75	$	—	$	—	$	—	$	75
Commingled funds	492		—		—		409		901		518		—		—		388		906
Debt securities	—		360		2		—		362		—		270		1		—		271
Equity securities	24		—		—		—		24		27		—		—		—		27
Other	—		3		—		12		15		2		2		—		—		4
Total	$	565	$	363	$	2	$	421	$	1,351	$	622	$	272	$	1	$	388	$	1,283

(a)See Note 8 for further information on fair value measurement inputs and methods.

	Dec. 31, 2021 (a)										Dec. 31, 2020 (a)
(Millions of Dollars)	Level 1		Level 2		Level 3		Measured at NAV		Total		Level 1		Level 2		Level 3		Measured at NAV		Total
Cash equivalents	$	25	$	—	$	—	$	—	$	25	$	24	$	—	$	—	$	—	$	24
Insurance contracts	—		46		—		—		46		—		45		—		—		45
Commingled funds	57		—		—		68		125		64		—		—		61		125
Debt securities	—		194		1		—		195		—		207		—		—		207
Other	—		2		—		—		2		—		3		—		—		3
Total	$	82	$	242	$	1	$	68	$	393	$	88	$	255	$	—	$	61	$	404

(a)See Note 8 for further information on fair value measurement inputs and methods

	Pension Benefits				Postretirement Benefits
	2021		2020		2021		2020
Domestic and international equity securities	33	%	35	%	15	%	15	%
Long-duration fixed income securities	37		35		—		—
Short-to-intermediate fixed income securities	11		13		71		72
Alternative investments	17		15		8		9
Cash	2		2		6		4
Total	100	%	100	%	100	%	100	%

Change in Projected Benefit Obligation

	Pension Benefits				Postretirement Benefits
(Millions of Dollars)	2021		2020		2021		2020
Change in Benefit Obligation:
Obligation at Jan. 1	$	1,428	$	1,330	$	415	$	380
Service cost	32		30		1		1
Interest cost	39		46		11		13
Plan amendments	—		—		—		—
Actuarial (gain) loss	(57)		102		(31)		52
Plan participants’ contributions	—		—		7		6
Medicare subsidy reimbursements	—		—		2		1
Benefit payments	(79)		(80)		(36)		(38)
Obligation at Dec. 31	$	1,363	$	1,428	$	369	$	415
Change in Fair Value of Plan Assets:
Fair value of plan assets at Jan. 1	$	1,283	$	1,124	$	404	$	401
Actual return on plan assets	102		189		15		32
Employer contributions	45		50		3		3
Plan participants’ contributions	—		—		7		6
Benefit payments	(79)		(80)		(36)		(38)
Fair value of plan assets at Dec. 31	$	1,351	$	1,283	$	393	$	404
Funded status of plans at Dec. 31	$	(12)	$	(145)	$	24	$	(11)
Amounts recognized in the Consolidated Balance Sheet at Dec. 31:
Noncurrent assets	6		—		24		—
Noncurrent liabilities	(18)		(145)		—		(11)
Net amounts recognized	$	(12)	$	(145)	$	24	$	(11)

Amounts Not Yet Recognized as Components of Net Periodic Benefit Costs Recorded on the Balance Sheet Based Upon Expected Recovery in Rates

	Pension Benefits				Postretirement Benefits
(Millions of Dollars)	2021		2020		2021		2020
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost:
Net loss	$	313	$	432	$	48	$	81
Prior service credit	(1)		(1)		(2)		(6)
Total	$	312	$	431	$	46	$	75
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery in Rates:
Current regulatory assets	$	24	$	25	$	—	$	—
Noncurrent regulatory assets	288		404		46		75
Deferred income taxes	—		1		—		—
Net-of-tax accumulated other comprehensive income	—		1		—		—
Total	$	312	$	431	$	46	$	75

Measurement date Dec. 31, 2021 Dec. 31, 2020 Dec. 31, 2021 Dec. 31, 2020

Components of Net Periodic Benefit Costs

Net Periodic Benefit Cost (Credit) — Net periodic benefit cost (credit), other than the service cost component, is included in other income (expense) in the statements of income.

Components of net periodic benefit cost (credit) and amounts recognized in other comprehensive income and regulatory assets and liabilities:

	Pension Benefits									Postretirement Benefits
(Millions of Dollars)	2021			2020			2019			2021			2020			2019
Service cost	$	32		$	30		$	26		$	1		$	—		$	1
Interest cost	39			46			52			11			13			15
Expected return on plan assets	(73)			(70)			(69)			(16)			(17)			(19)
Amortization of prior service credit	—			(3)			(3)			(4)			(4)			(5)
Amortization of net loss	32			30			25			3			1			3
Settlement charge (a)	—			—			3			—			—			—
Net periodic pension cost (credit)	30			33			34			(5)			(7)			(5)
Effects of regulation	—			4			4			2			3			1
Net benefit cost (credit) recognized for financial reporting	$	30		$	37		$	38		$	(3)		$	(4)		$	(4)
Significant Assumptions Used to Measure Costs:
Discount rate	2.71		%	3.49		%	4.31		%	2.65		%	3.47		%	4.32		%
Expected average long-term increase in compensation level	3.75			3.75			3.75			N/A			N/A			N/A
Expected average long-term rate of return on assets	6.38			6.84			6.84			4.10			4.50			4.50

(a)A settlement charge is required when the amount of all lump-sum distributions during the year is greater than the sum of the service and interest cost components of the annual net periodic pension cost. In 2019, as a result of lump-sum distributions during the plan year, PSCo recorded a total pension settlement charge of $3 million. An immaterial amount was recorded in the income statement in 2019. There were no settlement charges recorded to the qualified pension plans in 2021 or 2020.

Projected Benefit Payments for the Pension and Postretirement Benefit Plans

PSCo’s projected benefit payments:

(Millions of Dollars)	Projected Pension Benefit Payments		Gross Projected Postretirement Health Care Benefit Payments		Expected Medicare Part D Subsidies		Net Projected Postretirement Health Care Benefit Payments
2022	$	83	$	30	$	2	$	28
2023	82		29		2		27
2024	82		29		2		27
2025	82		28		2		26
2026	81		27		2		25
2027-2031	388		123		13		110