Employee Benefits (Tables)

12 Months Ended

Dec. 31, 2022

Employee Benefits

Schedule of Plans' assets measured at estimated fair value

	December 31,
(Millions of dollars)	2022		Level 1		Level 2		Level 3
Assets:
Domestic equity securities	$	84	$	84	$	—	$	—
Foreign equity securities		60		60		—		—
Domestic fixed income mutual funds		26		26		—		—
Foreign fixed income mutual funds		11		11		—		—
Money market funds		1		1		—		—
Total assets	$	182	$	182	$	—	$	—

	December 31,
(Millions of dollars)	2021		Level 1		Level 2		Level 3
Assets:
Domestic equity securities	$	113	$	113	$	—	$	—
Foreign equity securities		71		71		—		—
Domestic fixed income mutual funds		29		29		—		—
Foreign fixed income mutual funds		12		12		—		—
Money market funds		2		2		—		—
Total assets	$	227	$	227	$	—	$	—

Schedule of assumptions used in determining pension information for qualified and nonqualified plans

	Years ended December 31,
	2022				2021				2020
Weighted average assumptions:
Discount rate used to determine obligations	5.30	-	5.40	%	1.20	-	2.90	%	0.70	-	2.60	%
Discount rate used to determine net periodic benefit cost	1.20	-	2.90	%	0.70	-	2.60	%	2.15	-	3.50	%
Expected return on plan assets			6.25	%			6.25	%			6.25	%
Long-term rate of increase in compensation levels			4.00	%			4.00	%			4.00	%

Schedule of aggregate changes in the benefit obligation and fair value of assets for the qualified and nonqualified plans and the funded status

	December 31,
		2022	2021
(Millions of dollars)		Accumulated benefits exceed assets		Accumulated benefits exceed assets
Reconciliation of benefit obligation:
Benefit obligation at beginning of year	$	362	$	379
Service cost		9		10
Interest cost		10		9
Actuarial gains		(97)		(10)
Plan settlements		—		(19)
Benefits paid		(8)		(7)
Benefit obligation at end of year	$	276	$	362
Reconciliation of fair value of plan assets:
Fair value of plan assets at beginning of year	$	227	$	206
Actual return on plan assets		(38)		27
Employer contributions		1		20
Plan settlements		—		(19)
Benefits paid		(8)		(7)
Fair value of plan assets at end of year	$	182	$	227
Funded status	$	(94)	$	(135)

Schedule of net periodic benefit cost for all plans

	Years ended December 31,
(Millions of dollars)	2022		2021		2020
Components of net periodic benefit cost:
Service cost	$	9	$	10	$	9
Interest cost		10		9		11
Expected return on plan assets		(14)		(12)		(11)
Amortization		6		9		7
Settlement loss recognized		—		6		11
Net periodic benefit cost	$	11	$	22	$	27