Long-Term Debt - Additional Information (Detail)		1 Months Ended	12 Months Ended
	Jan. 15, 2021 USD ($)	Jan. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	May 03, 2019 USD ($)
Debt Disclosure [Line Items]
Debt Issuance Costs, Line of Credit Arrangements, Gross			$ 100,000	$ 2,600,000
Required covenant, current ratio			1.00
Second Lien Facility			$ 200,000,000	200,000,000
Debt Instrument, Discounted Percentage			98.00%
Accelerated Deferred Debt Issuance Cost			$ 900,000
Anti-hoarding provision, maximum cash			25,000,000
Subsequent Event
Debt Disclosure [Line Items]
Amortization Payment		$ 1,875,000
Credit Facility Availability		25.00%
Revolving Credit Facility
Debt Disclosure [Line Items]
Maximum borrowing capacity			$ 375,000,000		$ 1,000,000,000.0
Letter of credit amount outstanding				$ 400,000
Line of Credit Facility, Interest Rate at Period End			3.40%
Required covenant, debt to EBITDAX ratio			3.50
Line of Credit Facility, Current Borrowing Capacity			$ 350,000,000
Revolving Credit Facility | Subsequent Event
Debt Disclosure [Line Items]
Debt Issuance Costs, Line of Credit Arrangements, Gross		$ 400,000
Required covenant, debt to EBITDAX ratio		2.00
Payment for Debt Extinguishment or Debt Prepayment Cost	$ 80,500,000	$ 80,500,000
Revolving Credit Facility | Minimum [Member]
Debt Disclosure [Line Items]
Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR			1.50%
Revolving Credit Facility | Maximum [Member]
Debt Disclosure [Line Items]
Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR			2.50%
Credit facility interest rate option two, applicable margin rate			3.50%
Commitment fees for undrawn credit facility			0.50%
Second Lien Facility
Debt Disclosure [Line Items]
Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR			7.25%
Credit facility interest rate option two, applicable margin rate			8.25%
Second Lien Facility, Initial Interest Rate			8.34%
Second Lien Facility, Effective Interest Rate			9.89%
Interest Rate Floor			1.00%
Second Lien Facility | Interest Payable One [Member]
Debt Disclosure [Line Items]
Debt Instrument, Interest Payable Period			1 month
Second Lien Facility | Interest Payable Two [Member]
Debt Disclosure [Line Items]
Debt Instrument, Interest Payable Period			3 months
Second Lien Facility | Interest Payable Three [Member]
Debt Disclosure [Line Items]
Debt Instrument, Interest Payable Period			6 months
Second Lien Facility | Subsequent Event
Debt Disclosure [Line Items]
Debt Issuance Costs, Line of Credit Arrangements, Gross		$ 1,400,000
Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR		8.25%
Credit facility interest rate option two, applicable margin rate		9.25%
Repayments of Debt		$ 1,300,000
Asset Coverage Ratio		1.25
Payment for Debt Extinguishment or Debt Prepayment Cost	$ 50,000,000.0	$ 50,000,000.0
Write off Deferred Debit Issuance and Original Issuance Costs		$ 1,300,000
First Lien [Member]
Debt Disclosure [Line Items]
Required covenant, debt to EBITDAX ratio			2.50
Letter of Credit
Debt Disclosure [Line Items]
Maximum borrowing capacity			$ 25,000,000
Year 1 | Second Lien Facility
Debt Disclosure [Line Items]
Prepayment Premium			102.00%
Year 2 | Second Lien Facility
Debt Disclosure [Line Items]
Prepayment Premium			101.00%