Investment in Cenovus Energy (Tables) - Cenovus Energy Inc [Member]	12 Months Ended
	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Schedule of Investment in Common Shares Carried at Fair Value	December 31 2021 2020 Number of shares of CVE common stock (millions) 91 208 Ownership of issued and outstanding common stock 4.5 % 16.9 Closing price on NYSE on last trading day ($/share) $ 12.28 6.04 Fair Value (millions of dollars) $ 1,117 1,256
Gains and Losses Recorded in Other Income (Loss)	Millions of Dollars 2021 2020 2019 Total Net gain (loss) on equity securities $ 1,040 (855) 649 Less: Net gain (loss) on equity securities sold during the period 473 Unrealized gain (loss) on equity securities still held at the reporting date $ 567 (855) 649