XML 89 R71.htm IDEA: XBRL DOCUMENT v3.7.0.1
Asset Retirement Obligations, Classified Asset Retirement Obligations and Environmental Rehabilitation Trust (Details) - USD ($)
$ in Millions
Mar. 31, 2017
Dec. 31, 2016
Mar. 31, 2016
Dec. 31, 2015
Asset retirement obligations [Abstract]        
Current portion included in "Accrued liabilities" $ 5 $ 3    
Noncurrent portion included in "Asset retirement obligations" 74 73    
Asset retirement obligations 79 76 $ 87 $ 81
Environmental rehabilitation trust assets $ 14 $ 13