Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2022

Retirement Benefits [Abstract]

Company's pension and postretirement benefit plans

Components of net cost (benefit) for pension and other postretirement plans
	Three months ended September 30,				Nine months ended September 30,
($ in millions)	2022		2021		2022		2021
Pension benefits
Service cost	$	22	$	27	$	79	$	78
Interest cost	59		47		157		145
Expected return on plan assets	(85)		(112)		(295)		(338)
Amortization of prior service credit	(2)		(13)		(27)		(38)
Costs and expenses	(6)		(51)		(86)		(153)
Remeasurement of projected benefit obligation	(254)		(25)		(1,427)		(292)
Remeasurement of plan assets	335		68		1,563		(99)
Remeasurement (gains) losses	81		43		136		(391)
Pension net cost (benefit)	$	75	$	(8)	$	50	$	(544)
Postretirement benefits
Service cost	$	—	$	—	$	1	$	1
Interest cost	3		2		7		6
Amortization of prior service credit	(7)		(5)		(19)		(18)
Costs and expenses	(4)		(3)		(11)		(11)
Remeasurement of projected benefit obligation	(2)		(3)		(45)		(13)
Remeasurement of plan assets	—		—		—		—
Remeasurement (gains) losses	(2)		(3)		(45)		(13)
Postretirement net benefit	$	(6)	$	(6)	$	(56)	$	(24)
Pension and postretirement benefits
Costs and expenses	$	(10)	$	(54)	$	(97)	$	(164)
Remeasurement (gains) losses	79		40		91		(404)
Total net cost (benefit)	$	69	$	(14)	$	(6)	$	(568)

Pension and postretirement benefits remeasurement gains and losses
	Three months ended September 30,				Nine months ended September 30,
($ in millions)	2022		2021		2022		2021
Remeasurement of projected benefit obligation (gains) losses:
Discount rate	$	(284)	$	(32)	$	(1,289)	$	(271)
Other assumptions	28		4		(183)		(34)
Remeasurement of plan assets (gains) losses	335		68		1,563		(99)
Remeasurement (gains) losses	$	79	$	40	$	91	$	(404)