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Summary of Significant Accounting Policies - Summary of Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 23, 2020	Dec. 31, 2019
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Derivative financial instruments	$ 8,830		$ 75,304
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Derivative financial instruments	$ 63,595		222
7.5% Senior Notes due 2025
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Interest rate on debt instrument	7.50%
9.75% Senior Notes due 2026
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Interest rate on debt instrument	9.75%	9.75%
Bank Credit Facility
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt, Carrying Value	$ 500,000		1,250,000
Long-term debt, Fair Value	500,000		1,250,000
Level 1 \| 7.5% Senior Notes due 2025
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt, Carrying Value	467,917		455,768
Long-term debt, Fair Value	586,882		534,375
Level 1 \| 9.75% Senior Notes due 2026
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt, Carrying Value	1,575,554		820,057
Long-term debt, Fair Value	1,687,125		765,000
Derivative Financial Instruments \| Level 2 and Level 3
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Derivative financial instruments	10,015		89,192
Derivative financial asset, Fair value	10,015		89,192
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Derivative financial instruments	129,968		4,442
Derivative financial liabilities, Fair value	$ 129,968		$ 4,442