Income Taxes (Tables)

9 Months Ended

Sep. 30, 2017

Income Tax Disclosure [Abstract]

Summary of Unrecognized Tax Benefits [Table Text Block]

	Nine Months Ended September 30, 2017
	(Dollars in Millions)
Beginning balance	$	35
Tax positions related to current period:
Additions	2
Tax positions related to prior periods:
Reductions	(21		)
Effect of exchange rate changes	1
Ending balance	$	17