Investment in Cenovus Energy	12 Months Ended
Investment in Cenovus Energy	Dec. 31, 2019
Investment in Cenovus Energy [Abstract]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	Note 7—Investment in Cenovus Energy On May 17, 2017, we completed the sale of our 50 percent nonoperated interest in the FCCL Partnership, as well as the majority of our western Canada gas assets, to Cenovus Energy. Consideration for the transaction included 208 million Cenovus Energy common shares, which, at closing, approximated 16.9 percent of issued and outstanding Cenovus Energy common stock. See Note 5—Asset Acquisitions and Dispositions, for additional information on the Canada disposition. The fair value and cost basis of our investment in 208 million Cenovus Energy common shares was $ 1.96 billion based on a price of $ 9.41 per share on the NYSE on the closing date. Our investment on our consolidated balance sheet as of December 31, 2019, is carried at fair value of $ 2.11 billion, reflecting the closing price of Cenovus Energy shares on the NYSE of $ 10.15 per share, an increase of $ 649 million from $ 1.46 billion at December 31, 2018. The increase in fair value represents the net unrealized gain recorded within the “Other income” line of our consolidated income statement for the year ended December 31, 2019 relating to the shares held at the reporting date. See Note 15—Fair Value Measurement and Note 22—Other Financial Information, for additional information. Subject to market conditions, we intend to decrease our investment over time through market transactions, private agreements or otherwise.