Other Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Other Finite and Infinite Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Remaining Amortization Period	7 years
Intangible Assets Gross Excluding Goodwill	$ 54	$ 47
Intangible Assets Accumulated Amortization	18	13
Other intangible assets, net	36	34
Cost of Services, Amortization	6	6	$ 2
Other Intangible Assets [Member]
Schedule of Other Finite and Infinite Intangible Assets [Line Items]
Intangible Assets Gross Excluding Goodwill	4	4
Intangible Assets Accumulated Amortization	0	0
Other intangible assets, net	4	4
Customer Relationships [Member]
Schedule of Other Finite and Infinite Intangible Assets [Line Items]
Intangible Assets Gross Excluding Goodwill	50	43
Intangible Assets Accumulated Amortization	18	13
Other intangible assets, net	32	$ 30
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	6
Finite-Lived Intangible Assets, Amortization Expense, Year Two	6
Finite-Lived Intangible Assets, Amortization Expense, Year Three	5
Finite-Lived Intangible Assets, Amortization Expense, Year Four	4
Finite-Lived Intangible Assets, Amortization Expense, Year Five	4
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	$ 7