Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2024

Retirement Benefits [Abstract]

Schedule of Change in Projected Benefit Obligation, Plan Assets and Funded Status

Change in benefit obligation, plan assets and funded status
	As of December 31,
	Pension benefits				Postretirement benefits
($ in millions)	2024		2023		2024		2023
Change in benefit obligation
Benefit obligation, beginning of year	$	4,584	$	4,511	$	185	$	203
Service cost	80		132		—		1
Interest cost	230		239		9		10
Participant contributions	—		—		13		16
Remeasurement of benefit obligation (gains) losses	(125)		125		(4)		(4)
Benefits paid	(329)		(379)		(37)		(42)
Translation adjustment and other	1		(44)		(3)		1
Benefit obligation, end of year	$	4,441	$	4,584	$	163	$	185
Change in plan assets
Fair value of plan assets, beginning of year	$	4,440	$	4,430
Actual return on plan assets	214		418
Employer contribution	45		14
Benefits paid	(329)		(379)
Translation adjustment and other	(2)		(43)
Fair value of plan assets, end of year	$	4,368	$	4,440
Funded status (1)	$	(73)	$	(144)	$	(163)	$	(185)
Amounts recognized in AOCI
Unamortized pension and other postretirement prior service credit	$	—	$	—	$	(15)	$	(18)

(1)The funded status is recorded within other liabilities and accrued expenses on the Consolidated Statements of Financial Position.

Schedule of Changes in Items Not Yet Recognized as a Component of Net Cost for Pension and Other Postretirement Plans

Changes in items not yet recognized as a component of net cost for pension and other postretirement plans
($ in millions)	Pension benefits		Postretirement benefits
Items not yet recognized as a component of net cost – December 31, 2023	$	—	$	(18)
Prior service credit amortized to net cost	—		1
Translation adjustment and other	—		2
Items not yet recognized as a component of net cost – December 31, 2024	$	—	$	(15)

Schedule of Components of Net Cost (Benefit) for Pension and Other Postretirement Plans

Components of net cost (benefit) for pension and other postretirement plans
	For the years ended December 31,
	Pension benefits						Postretirement benefits						Total pension and postretirement benefits
($ in millions)	2024		2023		2022		2024		2023		2022		2024		2023		2022
Service cost	$	80	$	132	$	101	$	—	$	1	$	1	$	80	$	133	$	102
Interest cost	230		239		219		9		10		10		239		249		229
Expected return on plan assets	(306)		(306)		(371)		—		—		—		(306)		(306)		(371)
Amortization of prior service credit	—		—		(27)		(1)		(21)		(25)		(1)		(21)		(52)
Costs and expenses	4		65		(78)		8		(10)		(14)		12		55		(92)
Remeasurement of benefit obligation	(125)		125		(1,382)		(4)		(4)		(62)		(129)		121		(1,444)
Remeasurement of plan assets	92		(112)		1,560		—		—		—		92		(112)		1,560
Remeasurement (gains) losses	(33)		13		178		(4)		(4)		(62)		(37)		9		116
Total net (benefit) cost	$	(29)	$	78	$	100	$	4	$	(14)	$	(76)	$	(25)	$	64	$	24

Schedule of Weighted Average Assumptions Used to Determine Net Pension Cost and Net Postretirement Benefit Cost and Benefit Obligations

Weighted average assumptions used to determine net pension cost and net postretirement benefit cost
	For the years ended December 31,
	Pension benefits						Postretirement benefits
	2024		2023		2022		2024		2023		2022
Discount rate	5.36	%	5.65	%	4.27	%	5.30	%	5.66	%	4.24	%
Expected long-term rate of return on plan assets	7.34		7.35		7.06		n/a		n/a		n/a
Cash balance interest credit rate	4.25		4.05		2.74		n/a		n/a		n/a

Weighted average assumptions used to determine benefit obligations
	As of December 31,
	Pension benefits				Postretirement benefits
	2024		2023		2024		2023
Discount rate	5.71	%	5.35	%	5.50	%	5.28	%
Cash balance interest credit rate	4.78		4.03		n/a		n/a

Schedule of Pension Plan Weighted Average Target Asset Allocation by Asset Category

Pension plan weighted average target asset allocation by asset category (1)
	As of December 31, 2024
Equity securities	25% - 42%
Fixed income securities	53% - 69%
Limited partnership interests	1% - 28%
Short-term investments and other	NA
Bank loans	0% - 12%

(1)The target asset allocation considers risk-based exposure including exposure provided through derivatives.

Schedule of Fair Values of Pension Plan Assets

Fair values of pension plan assets as of December 31, 2024
($ in millions)	Quoted prices in active markets for identical assets (Level 1)			Significant other observable inputs (Level 2)			Significant unobservable inputs (Level 3)			Balance as of December 31, 2024
Equity securities	$	106		$	1		$	—		$	107
Fixed income securities:
Government bonds (1)	1,401			124			—			1,525
Corporate bonds (2)	—			985			—			985
Short-term investments	78			142			—			220
Free-standing derivatives:
Assets	—			9			—			9
Liabilities	(3)			(9)			—			(12)
Bank loans	—			—			81			81
Total plan assets at fair value	$	1,582		$	1,252		$	81		$	2,915
% of total plan assets at fair value	54.2		%	43.0		%	2.8		%	100.0		%
Investments measured using the net asset value practical expedient										1,570
Securities lending obligation (3)										(158)
Derivatives counterparty and cash collateral netting										(8)
Other net plan assets (4)										49
Total reported plan assets										$	4,368

Fair values of pension plan assets as of December 31, 2023
($ in millions)	Quoted prices in active markets for identical assets (Level 1)			Significant other observable inputs (Level 2)			Significant unobservable inputs (Level 3)			Balance as of December 31, 2023
Equity securities	$	132		$	28		$	—		$	160
Fixed income securities:
Government bonds (1)	323			1,007			—			1,330
Corporate bonds (2)	—			794			—			794
Short-term investments	154			144			—			298
Free-standing derivatives:
Assets	—			—			—			—
Liabilities	(1)			(8)			—			(9)
Other assets	1			—			—			1
Total plan assets at fair value	$	609		$	1,965		$	—		$	2,574
% of total plan assets at fair value	23.7		%	76.3		%	—		%	100.0		%
Investments measured using the net asset value practical expedient										$	2,019
Securities lending obligation (3)										(179)
Derivatives counterparty and cash collateral netting										8
Other net plan assets (4)										18
Total reported plan assets										$	4,440

(1)Includes U.S. government and agencies and foreign government bonds.

(2)Includes ABS securities.

(3)The securities lending obligation represents the plan’s obligation to return securities lending collateral received under a securities lending program. The terms of the program allow both the plan and the counterparty the right and ability to redeem/return the securities loaned on short notice. Due to its relatively short-term nature, the outstanding balance of the obligation approximates fair value.

(4)Other net plan assets represent cash and cash equivalents, interest and dividends receivable and net receivables related to settlements of investment transactions, such as purchases and sales.

Schedule of Rollforward of Level 3 Plan Assets

Rollforward of Level 3 plan assets during December 31, 2024
			Actual return on plan assets:
($ in millions)	Balance as of December 31, 2023		Relating to assets sold during the period		Relating to assets still held at the reporting date		Purchases, sales and settlements, net		Net transfers in (out) of Level 3		Balance as of December 31, 2024
Bank loans	$	—	$	—	$	—	$	81	$	—	$	81
Total Level 3 plan assets	$	—	$	—	$	—	$	81	$	—	$	81

Schedule of Estimated Future Benefit Payments Expected to be Paid

Estimated future benefit payments expected to be paid in the next 10 years
	As of December 31, 2024
($ in millions)	Pension benefits		Postretirement benefits
2025	$	489	$	21
2026	486		20
2027	466		19
2028	455		17
2029	450		15
2030-2034	1,772		54
Total benefit payments	$	4,118	$	146