Pensions and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2018

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Net Periodic Benefit Cost

The net periodic pension and other postretirement benefit costs for the three and nine months ended September 30, 2018 and 2017 were as follows:

	Pension
	Three Months Ended September 30						Nine Months Ended September 30
($ in millions)	2018			2017			2018			2017
Service cost		$8			$9			$24			$26
Interest cost	23			25			71			74
Expected return on plan assets	(37		)	(35		)	(113		)	(105		)
Amortization of actuarial losses	16			19			48			57
Pension settlement charge	—			—			—			22
Net periodic benefit cost		$10			$18			$30			$74

	Other Postretirement Benefits
	Three Months Ended September 30						Nine Months Ended September 30
($ in millions)	2018			2017			2018			2017
Service cost		$2			$1			$7			$6
Interest cost	6			6			18			18
Amortization of actuarial losses	5			3			14			9
Amortization of prior service credit	(15		)	(14		)	(45		)	(44		)
Net periodic benefit cost		($2	)		($4	)		($6	)		($11	)

Defined Contribution Plan Disclosures

	Three Months Ended September 30				Nine Months Ended September 30
($ in millions)	2018		2017		2018		2017
U.S. defined benefit pension contributions		$50		$—		$75		$29
Non-U.S. defined benefit pension mandatory contributions		$4		$6		$14		$14