Goodwill and Intangible Assets, Net Definite-lived and Indefinite-lived Intangible Assets Table (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Definite-lived intangible assets: [Abstract]
Gross carrying amount of definite-lived intangible assets	$ 686		$ 686		$ 712
Accumulated amortization of definite-lived intangible assets	(283)		(283)		(273)
Net carrying amount of definite-lived intangible assets	403		403		439
Net carrying amount of indefinite-lived intangible assets	62		62		62
Intangible assets, net	465		465		501
Amortization of Intangible Assets	11	$ 12	21	$ 24
Customer relationships
Definite-lived intangible assets: [Abstract]
Gross carrying amount of definite-lived intangible assets	399		399		396
Accumulated amortization of definite-lived intangible assets	(144)		(144)		(134)
Net carrying amount of definite-lived intangible assets	255		255		262
Other
Definite-lived intangible assets: [Abstract]
Gross carrying amount of definite-lived intangible assets	287		287		316
Accumulated amortization of definite-lived intangible assets	(139)		(139)		(139)
Net carrying amount of definite-lived intangible assets	148		148		$ 177
Metals Segment
Definite-lived intangible assets: [Abstract]
Finite-lived Intangible Assets Acquired	$ 12
Automotive Segment
Definite-lived intangible assets: [Abstract]
Finite-lived Intangible Assets Acquired			$ 1