Pensions and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2015

Pension Plan [Member]

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

Net Periodic Benefit Cost

The net periodic pension and other post-retirement benefit costs for the three and nine months ended September 30, 2015 and 2014 were as follows:

	Pensions
	Three Months Ended September 30						Nine Months Ended September 30
($ in millions)	2015			2014			2015			2014
Service cost	$	14		$	11		$	44		$	38
Interest cost	49			54			152			172
Expected return on plan assets	(76		)	(76		)	(215		)	(224		)
Amortization of actuarial losses	34			18			89			58
Amortization of prior service credit	(1		)	(1		)	(2		)	(2		)
Settlement losses	7			2			7			7
Curtailments and special termination benefits	1			—			2			—
Net periodic pension benefit cost	$	28		$	8		$	77		$	49

Other Postretirement Benefit Plan [Member]

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

Net Periodic Benefit Cost

	Other Postretirement Benefits
	Three Months Ended September 30						Nine Months Ended September 30
($ in millions)	2015			2014			2015			2014
Service cost	$	4		$	3		$	14		$	12
Interest cost	11			10			35			35
Amortization of actuarial losses	7			1			23			8
Amortization of prior service credit	(2		)	(2		)	(7		)	(7		)
Net periodic other postretirement benefit cost	$	20		$	12		$	65		$	48