Income Taxes (Unaudited) (Tables)

6 Months Ended

Jun. 30, 2016

Income Tax Disclosure [Abstract]

Schedule of Income Tax Expense and Effective Income Tax Rates

	Three Months Ended June 30						Six Months Ended June 30
$ in millions	2016			2015			2016			2015
Federal and foreign income tax expense	$	213		$	205		$	333		$	425
Effective income tax rate	29.2		%	27.9		%	23.7		%	29.5		%