Income Taxes (Tables)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

Our income tax expense and effective tax rate for the three months ended March 31 were as follows:

	Three months ended March 31,
(dollars in millions)	2018			2017
Income tax expense	$	9		$	29
Effective tax rate	20.0		%	34.5		%