Supplemental Oil and Gas Information (Unaudited) - Schedule of Product Prices Used for Valuing the Reserves (Detail)	12 Months Ended
	Dec. 31, 2020 $ / MMBTU $ / bbl	Dec. 31, 2019 $ / MMBTU $ / bbl
Oil [Member]
Supplemental Oil And Gas Reserve Information [Line Items]
Product prices for reserves	39.57	55.69
NGL [Member]
Supplemental Oil And Gas Reserve Information [Line Items]
Product prices for reserves	39.57	55.69
Natural Gas [Member]
Supplemental Oil And Gas Reserve Information [Line Items]
Product prices for reserves | $ / MMBTU	1.99	2.58