Debt Instruments - Convertible Debt Offerings (Details) - USD ($) |
Jun. 30, 2018 |
May 24, 2018 |
Dec. 31, 2017 |
Dec. 09, 2015 |
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| Debt Instrument [Line Items] | ||||
| Long-term debt, net | $ 250,267,000 | $ 273,014,000 | ||
| Share price (in dollars per share) | $ 7.88 | |||
| Convertible debt | Convertible senior notes due 2020 | ||||
| Debt Instrument [Line Items] | ||||
| Long-term debt, net | $ 152,100,000 | |||
| Value of debt | $ 145,700,000 | $ 233,500,000 | ||
| Debt instrument, conversion price (in dollars per share) | $ 16.42 | $ 16.42 | ||
| Aggregate principal amount | $ 157,400,000 | $ 345,000,000.0 | ||
| Convertible debt | Convertible senior notes due 2023 | ||||
| Debt Instrument [Line Items] | ||||
| Value of debt | $ 208,100,000 | $ 124,300,000 | ||
| Debt instrument, conversion price (in dollars per share) | $ 9.57 | $ 9.57 | ||
| Aggregate principal amount | $ 192,900,000 |
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- Definition The price per share of the conversion feature embedded in the debt instrument. 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 Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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