Benefit Plans and Other Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2024

Retirement Benefits [Abstract]

Components of Net Periodic Benefit Cost (Credit)

	Three Months Ended March 31
	2024		2023		2024		2023
(Millions of Dollars)	Pension Benefits				Postretirement Health Care Benefits
Service cost	$	5	$	5	$	—	$	—
Interest cost (a)	14		14		4		4
Expected return on plan assets (a)	(19)		(19)		(4)		(4)
Amortization of net loss (a)	2		1		1		1
Net periodic benefit cost	2		1		1		1
Effects of regulation	—		3		—		—
Net benefit cost recognized for financial reporting	$	2	$	4	$	1	$	1

(a)The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset.