Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Recurring | Level 2 | Commodity Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Commodity derivative contracts, net	$ (391)
Commodity derivative contracts, net		$ (667)
Nonrecurring | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Notes payable	368,822	373,374
Nonrecurring | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Notes payable	343,469	343,470
Nonrecurring | 2021 Notes | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Notes payable	28,790	373,374
Nonrecurring | 2021 Notes | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Notes payable	27,588	343,470
Nonrecurring | 2024 Notes | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Notes payable	49,886	0
Nonrecurring | 2024 Notes | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Notes payable	54,407	0
Nonrecurring | 2025 Notes | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Notes payable	290,146	0
Nonrecurring | 2025 Notes | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Notes payable	$ 261,474	$ 0