Revenue - Summary of Revenues Disaggregated (Detail) - USD ($) $ in Thousands	3 Months Ended								8 Months Ended	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Total revenues	$ 77,929	$ 72,959	$ 59,532	$ 65,155	$ 75,702	$ 85,522	$ 90,988	$ 87,932	$ 205,479	$ 275,575	$ 340,144
Oil and Natural Gas Sales [Member]
Revenues:
Total revenues									$ 205,176	274,607	339,840
Oil [Member]
Revenues:
Total revenues										192,944	209,066
NGLs [Member]
Revenues:
Total revenues										22,347	42,463
Natural Gas [Member]
Revenues:
Total revenues										$ 59,316	$ 88,311