Income Taxes (Unaudited) (Tables)

9 Months Ended

Sep. 30, 2016

Income Tax Disclosure [Abstract]

Schedule of Income Tax Expense and Effective Income Tax Rates

	Three Months Ended September 30						Nine Months Ended September 30
$ in millions	2016			2015			2016			2015
Federal and foreign income tax expense	$	167		$	213		$	500		$	638
Effective income tax rate	21.7		%	29.2		%	23.0		%	29.4		%