Stock-based Compensation Plans - PG/RG-PSUs Activities (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2021
Performance Share Units Production Growth Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Potential payout of shares granted	74.00%
Performance Share Units Reserve Growth Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Potential payout of shares granted	121.00%
Minimum [Member] | Performance-based Internal Performance Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Potential payout of shares granted	0.00%
Maximum | Performance-based Internal Performance Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Potential payout of shares granted	20.00%