Financial Risk Management Activities - Additional Information (Detail) - 2020 - Designated as Cash Flow Hedges	12 Months Ended
	Dec. 31, 2019 bbl / d $ / bbl
West Texas Intermediate
Derivative Instruments Gain Loss [Line Items]
Average monthly floor price | $ / bbl	55
Notional amount of outstanding average barrels of oil per day | bbl / d	130,000
Brent
Derivative Instruments Gain Loss [Line Items]
Average monthly floor price | $ / bbl	60
Notional amount of outstanding average barrels of oil per day | bbl / d	20,000