Summary of Significant Accounting Policies - Additional Information 4 (Detail)	12 Months Ended
	Dec. 31, 2017 USD ($) Segment Customer $ / shares shares	Dec. 31, 2016 USD ($) Customer $ / shares shares	Dec. 31, 2015 USD ($) Customer shares
Operations And Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | Segment	1
General and administrative expenses reimbursements of overhead costs	$ 11,700,000	$ 12,400,000	$ 13,900,000
Performance multiplier, minimum	0.00%
Performance multiplier, maximum	200.00%
Warrants for Common Stock exercise price | $ / shares	$ 0.01	$ 0.01
Participating securities that share in losses | shares	0	0	0
Interest costs, capitalized during period	$ 0	$ 0	$ 900,000
Interest paid in-kind	38,073,000	11,860,000
Convertible Notes
Operations And Summary Of Significant Accounting Policies [Line Items]
Interest paid in-kind	$ 38,100,000	$ 11,900,000
Restricted Stock
Operations And Summary Of Significant Accounting Policies [Line Items]
Shares of unvested restricted stock outstanding | shares	619,867	354,986	314,048
Major Oil and Natural Gas Purchaser
Operations And Summary Of Significant Accounting Policies [Line Items]
Number of major customers of oil and gas sales | Customer	4	4	2
Major Oil and Natural Gas Purchaser One
Operations And Summary Of Significant Accounting Policies [Line Items]
Percentage accounted of oil and gas sales	34.00%	42.00%	52.00%
Major Oil and Natural Gas Purchaser Two
Operations And Summary Of Significant Accounting Policies [Line Items]
Percentage accounted of oil and gas sales	17.00%	17.00%	25.00%
Major Oil and Natural Gas Purchaser Three
Operations And Summary Of Significant Accounting Policies [Line Items]
Percentage accounted of oil and gas sales	16.00%	14.00%
Major Oil and Natural Gas Purchaser Four
Operations And Summary Of Significant Accounting Policies [Line Items]
Percentage accounted of oil and gas sales	15.00%	12.00%