v3.21.2
Fair Value Measurement - FV Hierarchy (Details) - USD ($)
$ in Millions
Sep. 30, 2021
Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment in CVE shares $ 1,416 $ 1,256
Investments in debt securities 566 518
Commodity derivative asset, gross 1,710 255
Fair Value, Measurements, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment in CVE shares 1,416 1,256
Investments in debt securities 566 518
Commodity derivative asset, gross 1,710 255
Total assets 3,692 2,029
Commodity derivative liability, gross 1,775 220
Total liabilities 1,775 220
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment in CVE shares 1,416 1,256
Investments in debt securities 6 17
Commodity derivative asset, gross 882 142
Total assets 2,304 1,415
Commodity derivative liability, gross 893 120
Total liabilities 893 120
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment in CVE shares 0 0
Investments in debt securities 560 501
Commodity derivative asset, gross 788 101
Total assets 1,348 602
Commodity derivative liability, gross 723 91
Total liabilities 723 91
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment in CVE shares 0 0
Investments in debt securities 0 0
Commodity derivative asset, gross 40 12
Total assets 40 12
Commodity derivative liability, gross 159 9
Total liabilities $ 159 $ 9