Benefit Plans (Tables)

6 Months Ended

Jun. 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 June 30,				Six months ended June 30,
($ in millions)	2022		2021		2022		2021
Pension benefits
Service cost	$	28	$	25	$	57	$	51
Interest cost	52		52		98		98
Expected return on plan assets	(100)		(109)		(210)		(226)
Amortization of prior service credit	(12)		(12)		(25)		(25)
Costs and expenses	(32)		(44)		(80)		(102)
Remeasurement of projected benefit obligation	(421)		245		(1,173)		(267)
Remeasurement of plan assets	699		(388)		1,228		(167)
Remeasurement (gains) losses	278		(143)		55		(434)
Pension net cost (benefit)	$	246	$	(187)	$	(25)	$	(536)
Postretirement benefits
Service cost	$	1	$	1	$	1	$	1
Interest cost	2		2		4		4
Amortization of prior service credit	(6)		(7)		(12)		(13)
Costs and expenses	(3)		(4)		(7)		(8)
Remeasurement of projected benefit obligation	(19)		9		(43)		(10)
Remeasurement of plan assets	—		—		—		—
Remeasurement (gains) losses	(19)		9		(43)		(10)
Postretirement net (benefit) cost	$	(22)	$	5	$	(50)	$	(18)
Pension and postretirement benefits
Costs and expenses	$	(35)	$	(48)	$	(87)	$	(110)
Remeasurement (gains) losses	259		(134)		12		(444)
Total net cost (benefit)	$	224	$	(182)	$	(75)	$	(554)

Pension and postretirement benefits remeasurement gains and losses
	Three months ended June 30,				Six months ended June 30,
($ in millions)	2022		2021		2022		2021
Remeasurement of projected benefit obligation (gains) losses:
Discount rate	$	(420)	$	178	$	(1,005)	$	(239)
Other assumptions	(20)		76		(211)		(38)
Remeasurement of plan assets (gains) losses	699		(388)		1,228		(167)
Remeasurement (gains) losses	$	259	$	(134)	$	12	$	(444)