Long-Term Debt - Additional Information (Details) - Senior Notes |
Sep. 30, 2019 |
|---|---|
| 9.25% Senior Secured Notes, due 2023 | |
| Debt Instrument [Line Items] | |
| Debt instrument, percentage rate | 9.25% |
| 6.50% Notes, due 2021 | |
| Debt Instrument [Line Items] | |
| Debt instrument, percentage rate | 6.50% |