Fair Value Measurements - Carrying Values and Fair Values of Financial Liabilities (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative	$ 7,012	$ 1,709
Carrying Value | Notes Payable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	2,379	3,525
Carrying Value | Senior Secured Notes due 2024 | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	475,000	475,000
Carrying Value | Revolving Credit Facility | 2019 Credit Facility | Line of Credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	250,971	250,000
Fair Value | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative	0	0
Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative	7,012	1,709
Fair Value | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative	0	0
Fair Value | Notes Payable | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Fair Value | Notes Payable | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	2,379	3,650
Fair Value | Notes Payable | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Fair Value | Senior Secured Notes due 2024 | Senior Notes | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Fair Value | Senior Secured Notes due 2024 | Senior Notes | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	519,379	494,000
Fair Value | Senior Secured Notes due 2024 | Senior Notes | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Fair Value | Revolving Credit Facility | 2019 Credit Facility | Line of Credit | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	0	0
Fair Value | Revolving Credit Facility | 2019 Credit Facility | Line of Credit | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	250,971	250,000
Fair Value | Revolving Credit Facility | 2019 Credit Facility | Line of Credit | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	$ 0	$ 0