Schedule of Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
2018	$ 2
2019	2
2020	1
2021	1
2022	1
Other Intangible Assets | International
Finite-Lived Intangible Assets [Line Items]
Amortization expense included in other operating expenses	$ 2	$ 1	$ 1