Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Oil and natural gas properties, accumulated depletion (in dollars)	$ 20,204	$ 0
Other property, accumulated depreciation and amortization (in dollars)	$ 8,426	$ 12,859
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares issued	441,210,817	408,740,182
Common stock, shares outstanding	441,210,817	408,740,182