v3.20.2
Asset Acquisitions and Dispositions - Asset Acquisition - Textual (Details)
$ in Millions
1 Months Ended
Aug. 31, 2020
USD ($)
a
Sep. 30, 2020
USD ($)
Dec. 31, 2019
USD ($)
Asset Acquisition      
Asset retirement obligations and accrued environmental costs   $ 5,651 $ 5,352
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt   $ 3,900  
Canada Segment [Member] | Operating Segments [Member] | Montney [Member]      
Asset Acquisition      
Oil and Gas, Undeveloped Acreage, Net | a 295,000    
Noncontrolling Interest, Ownership Percentage by Parent 100.00%    
Additional Montney acreage [Member] | Canada Segment [Member] | Operating Segments [Member]      
Asset Acquisition      
Payments to Acquire Businesses, Gross $ 382    
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Liabilities $ 31    
Oil and Gas, Undeveloped Acreage, Net | a 140,000    
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment $ 490    
Asset retirement obligations and accrued environmental costs 77    
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt $ 31