Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016	Jun. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible Assets Including Goodwill Translation Adjustment		$ 4
Definite-Lived Intangible Assets [Abstract]
Finite-Lived Intangible Assets, Gross	$ 142	142	$ 135
Goodwill, Acquired During Period			0
Finite-Lived Intangible Assets, Accumulated Amortization	60	60	51
Net Carrying Value	82	82	84
Goodwill			45
Goodwill and Indefinite-lived Intangible Assets, Net	46	46	45
Goodwill and indefinite-lived intangible assets [Abstract]
Goodwill, Gross	46	46	45
Intangible Assets, Gross (Including Goodwill)	188	188	180
Intangible Assets Net Including Goodwill	128	128	129
Finite-lived Intangible Assets Acquired		4
Amortization expense	(3)	(9)
Future Amortization Expense, Year One	13	13
Finite-Lived Intangible Assets, Amortization Expense, Year Two	14	14
Finite-Lived Intangible Assets, Amortization Expense, Year Three	14	14
Finite-Lived Intangible Assets, Amortization Expense, Year Four	11	11
Finite-Lived Intangible Assets, Amortization Expense, Year Five	9	9
Other Finite-Lived Intangible Assets, Gross	2	$ 2
Developed Technology Rights [Member]
Definite-Lived Intangible Assets [Abstract]
Finite-Lived Intangible Asset, Useful Life		10 years
Finite-Lived Intangible Assets, Gross	41	$ 41	40
Finite-Lived Intangible Assets, Accumulated Amortization	28	28	25
Net Carrying Value	13	13	15
Goodwill and indefinite-lived intangible assets [Abstract]
Finite-lived Intangible Assets Acquired		0
Amortization expense		(3)
Finite Lived Intangible Assets, Foreign Currency Translation Gain (Loss)		$ 1
Customer Relationships [Member]
Definite-Lived Intangible Assets [Abstract]
Finite-Lived Intangible Asset, Useful Life		9 years
Finite-Lived Intangible Assets, Gross	85	$ 85	83
Finite-Lived Intangible Assets, Accumulated Amortization	31	31	25
Net Carrying Value	54	54	58
Goodwill and indefinite-lived intangible assets [Abstract]
Finite-lived Intangible Assets Acquired		0
Amortization expense		(6)
Finite Lived Intangible Assets, Foreign Currency Translation Gain (Loss)		$ 2
Software and Software Development Costs [Member]
Definite-Lived Intangible Assets [Abstract]
Finite-Lived Intangible Asset, Useful Life		3 years
Finite-Lived Intangible Assets, Gross	6	$ 6	4
Finite-Lived Intangible Assets, Accumulated Amortization	0	0
Net Carrying Value	6	6	4
Goodwill and indefinite-lived intangible assets [Abstract]
Capitalized Software Development Costs for Software Sold to Customers	2	2
Amortization expense		0
Finite Lived Intangible Assets, Foreign Currency Translation Gain (Loss)		$ 0
Other [Member]
Definite-Lived Intangible Assets [Abstract]
Finite-Lived Intangible Asset, Useful Life		32 years
Finite-Lived Intangible Assets, Gross	10	$ 10	8
Finite-Lived Intangible Assets, Accumulated Amortization	1	1	1
Net Carrying Value	9	9	7
Goodwill and indefinite-lived intangible assets [Abstract]
Amortization expense		0
Finite Lived Intangible Assets, Foreign Currency Translation Gain (Loss)		0
Goodwill [Member]
Definite-Lived Intangible Assets [Abstract]
Finite-Lived Intangible Assets, Accumulated Amortization	$ 0	0	$ 0
Goodwill [Member]
Goodwill and indefinite-lived intangible assets [Abstract]
Amortization expense		0
Goodwill, Foreign Currency Translation Gain (Loss)		$ 1
Scenario, Forecast [Member]
Goodwill and indefinite-lived intangible assets [Abstract]
Other Finite-Lived Intangible Assets, Gross				$ 2