Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Oil and natural gas properties, accumulated depreciation, depletion and amortization	$ 15,066	$ 12,950
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	65,000,000	65,000,000
Common stock, shares issued	10,221,008	10,054,816
Common stock, shares, outstanding	10,183,467	10,042,468
Treasury stock, shares	37,541	12,348