Financial Risk Management Activities - Credit Risk - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Letters of credit - outstanding amount	$ 259	$ 269
Integrated Companies
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration percentage of accounts receivable	50.00%
Independent E&P Companies
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration percentage of accounts receivable	31.00%
Refining & Marketing Companies
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration percentage of accounts receivable	3.00%
National Oil Companies
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration percentage of accounts receivable	9.00%
Storage & Transportation Companies
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration percentage of accounts receivable	3.00%
Others
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration percentage of accounts receivable	4.00%