Revenue - Summary of Revenues Disaggregated (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenues:
Total revenues	$ 202,144	$ 275,575
Oil and Natural Gas Sales [Member]
Revenues:
Total revenues	200,888	274,607
Oil [Member]
Revenues:
Total revenues	138,273	192,944
NGLs [Member]
Revenues:
Total revenues	20,064	22,347
Natural Gas [Member]
Revenues:
Total revenues	$ 42,551	$ 59,316