Investments, Loans and Long-Term Receivables (Narrative) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |
---|---|---|---|
Mar. 31, 2017 |
Sep. 30, 2017 |
Sep. 30, 2016 |
|
Schedule of Equity Method Investments [Line Items] | |||
Collection of advances/loans—related parties | $ 325 | $ 325 | $ 107 |
Dakota Access LLC and Energy Transfer Crude Oil Company, LLC | |||
Schedule of Equity Method Investments [Line Items] | |||
Collection of advances/loans—related parties | 250 | ||
WRB Refining LP | |||
Schedule of Equity Method Investments [Line Items] | |||
Collection of advances/loans—related parties | $ 75 |