Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Intangible assets with indefinite lives, gross	$ 124	$ 128
Intangible assets with indefinite lives, accumulated amortization	(6)	(6)
Intangible assets with indefinite lives, net	118	122
Intangible assets, gross	174	171
Intangible assets, accumulated amortization	(35)	(35)
Intangible assets, net	139	136
Trademarks and Patents
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	26	24
Finite-lived intangible assets, accumulated amortization	(21)	(20)
Finite-lived intangible assets, net	5	4
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	24	19
Finite-lived intangible assets, accumulated amortization	(8)	(9)
Finite-lived intangible assets, net	$ 16	$ 10