Fair Value Measurements - Carrying Amount and Estimated Fair Value of Long-Term Debt (Details) - Notes $ in Thousands	Dec. 31, 2019 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
2025 Notes	$ 158,174
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
2025 Notes	148,140
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
2025 Notes	158,174
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
2025 Notes	0
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
2025 Notes	$ 0