XML 69 R57.htm IDEA: XBRL DOCUMENT v3.19.1
Fair Value of Financial Instruments - Estimated Carrying Amounts and Fair Value of Financial Instruments Not Carried at Fair Value (Details) - USD ($)
$ in Millions
Mar. 31, 2019
Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions    
Long-term debt, including current portion $ 6,656 $ 6,691
Carrying Amount    
Fair Value, Balance Sheet Grouping, Financial Statement Captions    
Notes receivable 17 17
Long-term debt, including current portion 6,558 6,591
Fair Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions    
Notes receivable 14 14
Long-term debt, including current portion 6,971 6,697
Fair Value | Level 2    
Fair Value, Balance Sheet Grouping, Financial Statement Captions    
Long-term debt, including current portion 6,834 6,528
Fair Value | Level 3    
Fair Value, Balance Sheet Grouping, Financial Statement Captions    
Long-term debt, including current portion $ 137 $ 169