Pension and Other Postretirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2018

Defined Benefit Plan Disclosure [Line Items]

Components of net cost of defined benefit plans

The Company has defined benefit pension plans covering eligible employees in the United States and in certain of its international subsidiaries. The net periodic benefit cost of such plans consisted of the following components:



	Three Months Ended September 30,												Nine Months Ended September 30,
	2018						2017						2018						2017
($ in millions)	U.S.			International			U.S.			International			U.S.			International			U.S.			International
Service cost	$	77		$	56		$	80		$	66		$	245		$	181		$	234		$	189
Interest cost	109			43			114			44			324			134			341			127
Expected return on plan assets	(209		)	(106		)	(210		)	(101		)	(634		)	(326		)	(646		)	(292		)
Amortization of unrecognized prior service credit	(12		)	(3		)	(13		)	(3		)	(37		)	(10		)	(40		)	(8		)
Net loss amortization	63			21			46			25			174			64			135			72
Termination benefits	1			—			3			1			18			—			11			2
Curtailments	3			—			4			(1		)	7			(1		)	8			(1		)
Settlements	—			—			—			—			1			3			—			—
	$	32		$	11		$	24		$	31		$	98		$	45		$	43		$	89

Other Postretirement Benefit Plans

Defined Benefit Plan Disclosure [Line Items]

Components of net cost of defined benefit plans

The Company provides medical benefits, principally to its eligible U.S. retirees and similar benefits to their dependents, through its other postretirement benefit plans. The net credit of such plans consisted of the following components:



	Three Months Ended September 30,						Nine Months Ended September 30,
($ in millions)	2018			2017			2018			2017
Service cost	$	15		$	15		$	43		$	43
Interest cost	17			20			52			61
Expected return on plan assets	(21		)	(20		)	(63		)	(59		)
Amortization of unrecognized prior service credit	(21		)	(24		)	(63		)	(74		)
Net loss amortization	—			—			1			1
Termination benefits	—			—			2			1
Curtailments	(1		)	(1		)	(7		)	(6		)
	$	(11	)	$	(10	)	$	(35	)	$	(33	)