Long-Term Debt - Tabular Disclosure (Details) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Long-Term Debt | ||
| Total principal amount | $ 737,148 | $ 860,000 |
| Less: unamortized discount | (6,240) | (12,088) |
| Less: debt issuance costs, net | (6,899) | (10,258) |
| Total carrying amount | 724,009 | 837,654 |
| 2022 Notes | Senior notes | ||
| Long-Term Debt | ||
| Total principal amount | 409,148 | 500,000 |
| 2023 Notes | Senior notes | ||
| Long-Term Debt | ||
| Total principal amount | 150,000 | 250,000 |
| Revolving credit facility | Wells Fargo Bank N.A. | Revolver | Line of credit | ||
| Long-Term Debt | ||
| Total principal amount | $ 178,000 | $ 110,000 |