Debt Instruments - Convertible Debt Offerings (Details) - USD ($) $ / shares in Units, $ in Thousands |
Sep. 30, 2018 |
May 24, 2018 |
Dec. 31, 2017 |
Dec. 09, 2015 |
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| Debt Instrument [Line Items] | ||||
| Share price (in dollars per share) | $ 9.51 | |||
| Convertible debt | Convertible senior notes due 2020 | ||||
| Debt Instrument [Line Items] | ||||
| Value of debt | $ 148,700 | $ 233,500 | ||
| Debt instrument, conversion price (in dollars per share) | $ 16.42 | $ 16.42 | ||
| Principal amount | $ 152,100 | $ 345,000 | ||
| Convertible debt | Convertible senior notes due 2023 | ||||
| Debt Instrument [Line Items] | ||||
| Value of debt | $ 222,700 | $ 124,300 | ||
| Debt instrument, conversion price (in dollars per share) | $ 9.57 | $ 9.57 | ||
| Principal amount | $ 192,900 | $ 0 |
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- Definition Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The price per share of the conversion feature embedded in the debt instrument. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Price of a single share of a number of saleable stocks of a company. No definition available.
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