Benefit Plans and Other Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2022

Benefit Plans and Other Postretirement Benefits [Abstract]

Target Asset Allocations and Plan Assets Measured at Fair Value

For each of the fair value hierarchy levels, PSCo’s pension plan assets measured at fair value:

	Dec. 31, 2022 (a)										Dec. 31, 2021 (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	$	52	$	—	$	—	$	—	$	52	$	49	$	—	$	—	$	—	$	49
Commingled funds	355		—		—		317		672		492		—		—		409		901
Debt securities	—		286		1		—		287		—		360		2		—		362
Equity securities	17		—		—		—		17		24		—		—		—		24
Other	—		3		—		—		3		—		3		—		12		15
Total	$	424	$	289	$	1	$	317	$	1,031	$	565	$	363	$	2	$	421	$	1,351

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

	Dec. 31, 2022 (a)										Dec. 31, 2021 (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	$	28	$	—	$	—	$	—	$	28	$	25	$	—	$	—	$	—	$	25
Insurance contracts	—		36		—		—		36		—		46		—		—		46
Commingled funds	47		—		—		56		103		57		—		—		68		125
Debt securities	—		153		1		—		154		—		194		1		—		195
Other	—		(1)		—		—		(1)		—		2		—		—		2
Total	$	75	$	188	$	1	$	56	$	320	$	82	$	242	$	1	$	68	$	393

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

	Pension Benefits				Postretirement Benefits
	2022		2021		2022		2021
Domestic and international equity securities	33	%	33	%	16	%	15	%
Long-duration fixed income securities	38		37		—		—
Short-to-intermediate fixed income securities	9		11		71		71
Alternative investments	18		17		12		8
Cash	2		2		1		6
Total	100	%	100	%	100	%	100	%

Change in Projected Benefit Obligation

	Pension Benefits				Postretirement Benefits
(Millions of Dollars)	2022		2021		2022		2021
Change in Benefit Obligation:
Obligation at Jan. 1	$	1,363	$	1,428	$	369	$	415
Service cost	29		32		1		1
Interest cost	41		39		10		11
Actuarial gain	(317)		(57)		(55)		(31)
Plan participants’ contributions	—		—		7		7
Medicare subsidy reimbursements	—		—		1		2
Benefit payments	(84)		(79)		(37)		(36)
Obligation at Dec. 31	$	1,032	$	1,363	$	296	$	369
Change in Fair Value of Plan Assets:
Fair value of plan assets at Jan. 1	$	1,351	$	1,283	$	393	$	404
Actual return on plan assets	(276)		102		(46)		15
Employer contributions	40		45		3		3
Plan participants’ contributions	—		—		7		7
Benefit payments	(84)		(79)		(37)		(36)
Fair value of plan assets at Dec. 31	$	1,031	$	1,351	$	320	$	393
Funded status of plans at Dec. 31	$	(1)	$	(12)	$	24	$	24
Amounts recognized in the Consolidated Balance Sheet at Dec. 31:
Noncurrent assets	8		6		24		24
Noncurrent liabilities	(9)		(18)		—		—
Net amounts recognized	$	(1)	$	(12)	$	24	$	24

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)	2022		2021		2022		2021
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost:
Net loss	$	325	$	313	$	53	$	48
Prior service credit	(1)		(1)		—		(2)
Total	$	324	$	312	$	53	$	46
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	$	3	$	24	$	—	$	—
Noncurrent regulatory assets	320		288		53		46
Net-of-tax accumulated other comprehensive income	1		—		—		—
Total	$	324	$	312	$	53	$	46

Measurement date Dec. 31, 2022 Dec. 31, 2021 Dec. 31, 2022 Dec. 31, 2021

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)	2022			2021			2020			2022			2021			2020
Service cost	$	29		$	32		$	30		$	1		$	1		$	—
Interest cost	41			39			46			10			11			13
Expected return on plan assets	(78)			(73)			(70)			(15)			(16)			(17)
Amortization of prior service credit	—			—			(3)			(2)			(4)			(4)
Amortization of net loss	23			32			30			1			3			1
Settlement charge (a)	3			—			—			—			—			—
Net periodic pension cost (credit)	18			30			33			(5)			(5)			(7)
Effects of regulation	4			—			4			3			2			3
Net benefit cost (credit) recognized for financial reporting	$	22		$	30		$	37		$	(2)		$	(3)		$	(4)
Significant Assumptions Used to Measure Costs:
Discount rate	3.08		%	2.71		%	3.49		%	3.09		%	2.65		%	3.47		%
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	6.39			6.38			6.84			4.10			4.10			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 2022, 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 2022. 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
2023	$	82	$	31	$	2	$	29
2024	82		30		2		28
2025	82		29		2		27
2026	82		29		2		27
2027	81		28		2		26
2028-2032	388		124		11		113