XML 80 R67.htm IDEA: XBRL DOCUMENT v3.10.0.1
Debt (Estimated Fair Value of Significant Financial Instruments) (Details) - USD ($)
$ in Millions
Jun. 30, 2018
Dec. 31, 2017
Carrying Amount    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Short-term debt $ 439 $ 262
Long-term debt 5,813 5,225
Fair Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Short-term debt 440 264
Long-term debt $ 5,826 $ 5,444