Benefit Plans

3 Months Ended

Mar. 31, 2021

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)	2021		2020
Pension benefits
Service cost	$	26	$	28
Interest cost	46		56
Expected return on plan assets	(117)		(104)
Amortization of prior service credit	(13)		(14)
Costs and expenses	(58)		(34)
Remeasurement of projected benefit obligation	(512)		(116)
Remeasurement of plan assets	221		434
Remeasurement (gains) losses	(291)		318
Pension net (benefit) cost	$	(349)	$	284
Postretirement benefits
Service cost	$	—	$	1
Interest cost	2		3
Amortization of prior service credit	(6)		(1)
Costs and expenses	(4)		3
Remeasurement of projected benefit obligation	(19)		—
Remeasurement of plan assets	—		—
Remeasurement (gains) losses	(19)		—
Postretirement net (benefit) cost	$	(23)	$	3
Pension and postretirement benefits
Costs and expenses	$	(62)	$	(31)
Remeasurement (gains) losses	(310)		318
Total net (benefit) cost	$	(372)	$	287

Differences between expected and actual returns on plan assets and changes in assumptions affect the Company’s pension and other postretirement obligations, plan assets and expenses.

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 Statement of Operations.

Pension and postretirement benefits remeasurement gains and losses
	Three months ended March 31,
($ in millions)	2021		2020
Remeasurement of projected benefit obligation (gains) losses:
Discount rate	$	(417)	$	(36)
Other assumptions	(114)		(80)
Remeasurement of plan assets (gains) losses	221		434
Remeasurement (gains) losses	$	(310)	$	318

Remeasurement gains for the first quarter of 2021 primarily related to an increase in the discount rate and changes in actuarial assumptions, partially offset by unfavorable asset performance compared to the expected return on plan assets.

The weighted average discount rate used to measure the benefit obligation increased to 3.13% at March 31, 2021 compared to 2.51% at December 31, 2020 resulting in gains for the first quarter of 2021.

Remeasurement gains for other assumptions in the first quarter of 2021 are primarily related to an increase in the long-term lump sum interest rate, partially offset by a remeasurement loss from an increase in the long-term cash balance interest crediting rate.

For the first quarter of 2021, the actual return on plan assets was lower than the expected return due to higher market yields resulting in lower fixed income valuations partially offset by strong equity performance.