Goodwill and Intangible Assets, Net Definite-lived and Indefinite-lived Intangible Assets Table (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Definite-lived intangible assets: [Abstract]
Gross carrying amount of definite-lived intangible assets	$ 679				$ 679		$ 712
Accumulated amortization of definite-lived intangible assets	(292)				(292)		(273)
Net carrying amount of definite-lived intangible assets	387				387		439
Net carrying amount of indefinite-lived intangible assets	62				62		62
Intangible assets, net	449				449		501
Amortization of intangible assets	10			$ 12	31	$ 36
Customer relationships
Definite-lived intangible assets: [Abstract]
Gross carrying amount of definite-lived intangible assets	395				395		396
Accumulated amortization of definite-lived intangible assets	(149)				(149)		(134)
Net carrying amount of definite-lived intangible assets	246				246		262
Other
Definite-lived intangible assets: [Abstract]
Gross carrying amount of definite-lived intangible assets	284				284		316
Accumulated amortization of definite-lived intangible assets	(143)				(143)		(139)
Net carrying amount of definite-lived intangible assets	$ 141				$ 141		$ 177
Metals Segment
Definite-lived intangible assets: [Abstract]
Definite-lived intangible assets acquired		$ 6
Automotive Segment
Definite-lived intangible assets: [Abstract]
Definite-lived intangible assets acquired			$ 1