Pension and Other Postretirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2017

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 (credit) of such plans consisted of the following components:



	Three Months Ended September 30,												Nine Months Ended September 30,
	2017						2016						2017						2016
($ in millions)	U.S.			International			U.S.			International			U.S.			International			U.S.			International
Service cost	$	80		$	66		$	66		$	59		$	234		$	189		$	212		$	179
Interest cost	114			44			116			51			341			127			342			155
Expected return on plan assets	(210		)	(101		)	(203		)	(95		)	(646		)	(292		)	(623		)	(288		)
Amortization of unrecognized prior service credit	(13		)	(3		)	(14		)	(3		)	(40		)	(8		)	(41		)	(9		)
Net loss amortization	46			25			32			21			135			72			89			64
Termination benefits	3			1			6			1			11			2			11			2
Curtailments	4			(1		)	3			(2		)	8			(1		)	3			(1		)
	$	24		$	31		$	6		$	32		$	43		$	89		$	(7	)	$	102

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 cost (credit) of such plans consisted of the following components:



	Three Months Ended September 30,						Nine Months Ended September 30,
($ in millions)	2017			2016			2017			2016
Service cost	$	15		$	14		$	43		$	41
Interest cost	20			19			61			62
Expected return on plan assets	(20		)	(19		)	(59		)	(88		)
Amortization of unrecognized prior service credit	(24		)	(26		)	(74		)	(79		)
Net loss amortization	—			1			1			1
Termination benefits	—			1			1			1
Curtailments	(1		)	(5		)	(6		)	(7		)
	$	(10	)	$	(15	)	$	(33	)	$	(69	)