Company Restructuring (Tables)

12 Months Ended

Dec. 31, 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	50			20			70
Adjustments to liability	(1		)	(2		)	(3		)
Payments and non-cash pension settlements	(35		)	(33		)	(68		)
Restructuring liability as of December 31, 2018	$	29		$	15		$	44