Long-Term Debt - Additional Information (Detail) - USD ($) $ in Thousands	4 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 03, 2019
Debt Disclosure [Line Items]
Interest on borrowings and related fees	$ 6,995	$ 36,593	$ 32,164
Amortization of debt issuance costs 2	1,961	2,611	2,736
Interest Paid, Capitalized, Investing Activities	(2,725)	(4,136)	(9,118)
Interest Expense	$ 6,392	35,811	26,462	$ 6,392
Debt Issuance Costs, Line of Credit Arrangements, Gross		$ 2,600	900
Line of credit, redetermination period		6 months
Write off of Deferred Debt Issuance Cost				$ 800
Line of credit , extension period		91 days
Required covenant, current ratio		1.00
Term of credit facility		5 years
Second Lien Facility		$ 200,000	$ 200,000
Proceeds from Debt, Net of Issuance Costs		187,800
Debt Instrument, Unamortized Discount		4,000
Unamortized Debt Issuance Expense		$ 8,200
Debt Instrument, Discounted Percentage		98.00%
Revolving Credit Facility [Member]
Debt Disclosure [Line Items]
Maximum borrowing capacity		$ 500,000			$ 1,000,000
Line of Credit Facility, Interest Rate at Period End		3.75%
Required covenant, debt to EBITDAX ratio		4.00
Revolving Credit Facility [Member] | Minimum [Member]
Debt Disclosure [Line Items]
Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR		0.50%
Revolving Credit Facility [Member] | Maximum [Member]
Debt Disclosure [Line Items]
Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR		1.50%
Credit facility interest rate option two, applicable margin rate		2.50%
Revolving credit facility
Debt Disclosure [Line Items]
Letter of credit amount outstanding		$ 400
Revolving credit facility | Letter of Credit
Debt Disclosure [Line Items]
Maximum borrowing capacity		$ 25,000
Letter of Credit | Minimum [Member]
Debt Disclosure [Line Items]
Commitment fees for undrawn credit facility		0.375%
Letter of Credit | Maximum [Member]
Debt Disclosure [Line Items]
Commitment fees for undrawn credit facility		0.50%
Second Lien Facility [Member]
Debt Disclosure [Line Items]
Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR		7.00%
Credit facility interest rate option two, applicable margin rate		6.00%
Second Lien Facility, Initial Interest Rate		8.34%
Second Lien Facility, Effective Interest Rate		9.89%
Year 3 [Member]
Debt Disclosure [Line Items]
Prepayment Premium		101.00%
Prepayment Premium, Change in Control		101.00%