Benefit Plans

3 Months Ended

Mar. 31, 2024

Retirement Benefits [Abstract]

Benefit Plans

Note 14 Benefit Plans

Components of net cost (benefit) for pension and other postretirement plans
	Three months ended March 31,
($ in millions)	2024		2023
Pension benefits
Service cost	$	33	$	33
Interest cost	58		60
Expected return on plan assets	(77)		(77)
Amortization of prior service credit	—		—
Costs and expenses	14		16
Remeasurement of projected benefit obligation	(25)		123
Remeasurement of plan assets	25		(180)
Remeasurement (gains) losses	—		(57)
Pension net cost (benefit)	$	14	$	(41)
Postretirement benefits
Service cost	$	—	$	—
Interest cost	2		3
Amortization of prior service credit	—		(6)
Costs and expenses	2		(3)
Remeasurement of projected benefit obligation	(2)		4
Remeasurement of plan assets	—		—
Remeasurement (gains) losses	(2)		4
Postretirement net cost	$	—	$	1
Pension and postretirement benefits
Costs and expenses	$	16	$	13
Remeasurement (gains) losses	(2)		(53)
Total net cost (benefit)	$	14	$	(40)

Differences in actual experience and changes in other assumptions affect our pension and other postretirement obligations and expenses. Differences between expected and actual returns on plan assets affect remeasurement (gains) losses.

Pension and other postretirement service cost, interest cost, expected return on plan assets and

amortization of prior service credit are reported in property and casualty insurance claims and claims expense, operating costs and expenses, net investment income and (if applicable) restructuring and related charges on the Condensed Consolidated Statements of Operations.

Pension and postretirement benefits remeasurement gains and losses
	Three months ended March 31,
($ in millions)	2024		2023
Remeasurement of projected benefit obligation (gains) losses:
Discount rate	$	(41)	$	124
Other assumptions	14		3
Remeasurement of plan assets (gains) losses	25		(180)
Remeasurement (gains) losses	$	(2)	$	(53)

Remeasurement gains for the first quarter of 2024 are primarily related to an increase in the liability discount rate, partially offset by unfavorable asset performance compared to expected return on plan assets.

The weighted average discount rate used to measure the pension benefit obligation increased to

5.45% at March 31, 2024 compared to 5.35% at December 31, 2023, resulting in gains for the first quarter of 2024.

For the first quarter of 2024, the actual return on plan assets was lower than the expected return due to lower fixed income valuations from higher market yields, partially offset by strong public equity returns.