v3.21.1
Debt - Debt assumed (Details) - Concho Resources Inc [Member] - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2021
Jan. 15, 2021
Debt Instrument [Line Items]    
Long-term debt   $ 4,696
3.75% Notes due 2027    
Debt Instrument [Line Items]    
Debt Instrument, Interest Rate, Stated Percentage   3.75%
Debt Instrument, Maturity Date, Description 2027  
Long-term debt   $ 1,000
4.3% Notes due 2028    
Debt Instrument [Line Items]    
Debt Instrument, Interest Rate, Stated Percentage   4.30%
Debt Instrument, Maturity Date, Description 2028  
Long-term debt   $ 1,000
2.4% Notes due 2031    
Debt Instrument [Line Items]    
Debt Instrument, Interest Rate, Stated Percentage   2.40%
Debt Instrument, Maturity Date, Description 2031  
Long-term debt   $ 500
4.875% Notes due 2047    
Debt Instrument [Line Items]    
Debt Instrument, Interest Rate, Stated Percentage   4.875%
Debt Instrument, Maturity Date, Description 2047  
Long-term debt   $ 800
4.85% Notes due 2048    
Debt Instrument [Line Items]    
Debt Instrument, Interest Rate, Stated Percentage   4.85%
Debt Instrument, Maturity Date, Description 2048  
Long-term debt   $ 600