Fair Value Measurements (Narrative) (Details) - USD ($) |
3 Months Ended | |||
|---|---|---|---|---|
Mar. 31, 2019 |
Dec. 31, 2018 |
May 25, 2018 |
Dec. 15, 2014 |
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| Fair Value Measurements | ||||
| Fair value asset transfers between Levels 1, 2 and 3 | $ 0 | |||
| Convertible Notes due 2023 | 297,392,000 | $ 294,725,000 | ||
| Recurring Basis | ||||
| Fair Value Measurements | ||||
| Asset value | 6,346,000 | |||
| 2019 Convertible Notes | ||||
| Fair Value Measurements | ||||
| Face amount | $ 172,500,000 | |||
| Debt instrument, fair value disclosure | 192,165,000 | 174,101,000 | ||
| 2023 Convertible Notes | ||||
| Fair Value Measurements | ||||
| Face amount | $ 345,000,000 | |||
| Debt instrument, fair value disclosure | 397,544,000 | 339,024,000 | ||
| Carrying Value | 2019 Convertible Notes | ||||
| Fair Value Measurements | ||||
| Convertible Notes due 2023 | 167,442,000 | 165,711,000 | ||
| Carrying Value | 2023 Convertible Notes | ||||
| Fair Value Measurements | ||||
| Convertible Notes due 2023 | 297,392,000 | $ 294,725,000 | ||
| Other Noncurrent Assets | Recurring Basis | ||||
| Fair Value Measurements | ||||
| Asset value | $ 6,746,000 |
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- Definition The fair value transfers between levels 1 2 and 3. No definition available.
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- Definition Carrying amount of long-term convertible debt as of the balance sheet date, net of the amount due in the next twelve months or greater than the normal operating cycle, if longer. The debt is convertible into another form of financial instrument, typically the entity's common stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Face (par) amount of debt instrument at time of issuance. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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/presentationRef
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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 Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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