Pension and Other Postretirement Benefit Plans (Tables)

6 Months Ended

Jun. 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 June 30,												Six Months Ended June 30,
	2017						2016						2017						2016
($ in millions)	U.S.			International			U.S.			International			U.S.			International			U.S.			International
Service cost	$	77		$	63		$	73		$	62		$	154		$	124		$	146		$	120
Interest cost	113			42			113			52			226			83			226			105
Expected return on plan assets	(218		)	(97		)	(210		)	(97		)	(436		)	(191		)	(420		)	(193		)
Amortization of unrecognized prior service credit	(13		)	(3		)	(14		)	(3		)	(27		)	(5		)	(27		)	(6		)
Net loss amortization	44			24			29			21			89			47			57			43
Termination benefits	3			1			1			—			8			2			5			—
Curtailments	1			(1		)	—			—			4			(1		)	—			1
	$	7		$	29		$	(8	)	$	35		$	18		$	59		$	(13	)	$	70

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 June 30,						Six Months Ended June 30,
($ in millions)	2017			2016			2017			2016
Service cost	$	14		$	13		$	28		$	27
Interest cost	20			21			40			42
Expected return on plan assets	(20		)	(34		)	(39		)	(69		)
Amortization of unrecognized prior service credit	(24		)	(26		)	(49		)	(53		)
Termination benefits	—			—			1			1
Curtailments	(2		)	(1		)	(5		)	(2		)
	$	(12	)	$	(27	)	$	(24	)	$	(54	)