Income Taxes (Unaudited) (Tables)

6 Months Ended

Jun. 30, 2018

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	2018			2017			2018			2017
Federal and foreign income tax expense	$	160		$	257		$	292		$	395
Effective income tax rate	18.8		%	31.7		%	17.0		%	24.7		%