Acquisitions and Dispositions - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) a Well
Business Acquisition [Line Items]
Purchase of non-controlling interests	$ 499,000	$ 65,000
Capital expenditures, including exploration expense	18,046,000	47,073,000
Proceeds from sale of property and equipment	4,579,000	$ 3,233,000
Reagan County, Texas [Member] | Mineral Acreage [Member]
Business Acquisition [Line Items]
Number of net acres acquired | a		464
Number of gross mineral acres acquired | a		1,640
Capital expenditures, including exploration expense		$ 6,080,000
Number of oil wells with working interest ownership		51
Number of commercial salt water disposal well operated | Well		1
Reagan County, Texas [Member] | Mineral Acreage [Member] | Minimum [Member]
Business Acquisition [Line Items]
Percentage of working interest ownership		16.60%
Reagan County, Texas [Member] | Mineral Acreage [Member] | Maximum [Member]
Business Acquisition [Line Items]
Percentage of working interest ownership		33.40%
Oklahoma Kansas Colorado and Texas [Member] | Mineral Acreage [Member]
Business Acquisition [Line Items]
Proceeds from sale of property and equipment	$ 4,300,000	$ 3,100,000