XML 71 R53.htm IDEA: XBRL DOCUMENT v3.8.0.1
Regulatory Matters, Commitments, Contingencies And Environmental Liabilities Table - Accrued Environmental Liabilities (Details) - USD ($)
$ in Millions
Mar. 31, 2018
Dec. 31, 2017
Environmental Exit Cost [Line Items]    
Current $ 54 $ 35
Non-current 326 337
Total environmental liabilities $ 380 $ 372