Company Restructuring (Tables)

9 Months Ended

Sep. 30, 2018

Restructuring and Related Activities [Abstract]

Schedule of changes in the restructuring liability

Restructuring activity during the period
($ in millions)	Employee costs			Exit costs			Total liability
Restructuring liability as of December 31, 2017	$	15		$	30		$	45
Expense incurred	41			26			67
Adjustments to liability	—			(2		)	(2		)
Payments and non-cash pension settlements	(20		)	(38		)	(58		)
Restructuring liability as of September 30, 2018	$	36		$	16		$	52