Other Assets (Details) - USD ($) $ in Millions	Sep. 30, 2015	Jul. 24, 2015	Dec. 31, 2014
Other current assets:
Prepaid assets	$ 105		$ 147
Restricted cash	5
Refinery metal inventory and receivable			606
Other refinery metal receivables			124
Derivative instruments			1
Other	6		3
Other current assets, total	116		881
Other long-term assets:
Income tax receivable	226		215
Restricted cash	179		127
Prepaid royalties	125		125
Goodwill	105		105
Intangible assets	102		109
Taxes other than income and mining	55		59
Debt issuance costs	50		58
Prepaid maintenance costs	34		30
Other	52		55
Other long-term assets, total	$ 928		$ 883
EGR
Other long-term assets:
Ownership interest sold (as a percent)	60.64%
Disposal by sale | EGR
Other long-term assets:
Ownership interest sold (as a percent)		60.64%