Pensions and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2020

Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]

Pension and Other Postretirement Benefit Cost Components

Pension and postretirement benefit cost components for the second quarter and first six months were as follows:

					Other Postretirement
	Pension Benefits				Benefits
	Second Quarter
	2020		2019		2020		2019
	($ in millions)
Service cost	$	10	$	8	$	2	$	1
Interest cost	18		23		3		5
Expected return on plan assets	(47)		(44)		(3)		(3)
Amortization of net losses	13		11		—		—
Amortization of prior service benefit	—		—		(7)		(6)
Net benefit	$	(6)	$	(2)	$	(5)	$	(3)

					Other Postretirement
	Pension Benefits				Benefits
	First Six Months
	2020		2019		2020		2019
	($ in millions)
Service cost	$	20	$	17	$	3	$	3
Interest cost	37		46		6		9
Expected return on plan assets	(95)		(89)		(6)		(7)
Amortization of net losses	26		22		—		—
Amortization of prior service benefit	—		—		(13)		(12)
Net benefit	$	(12)	$	(4)	$	(10)	$	(7)