Long-term Debt - Summary of Components of Convertible Notes (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
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| Debt Instrument [Line Items] | |||
| Interest expense | $ 76,874,000 | $ 65,472,000 | $ 45,241,000 |
| Convertible Notes Payable [Member] | 4.125% Convertible Senior Notes Due September 1, 2022 [Member] | |||
| Debt Instrument [Line Items] | |||
| Principal | 150,000,000 | 150,000,000 | |
| Accrued interest | 2,000,000 | 3,000,000 | |
| Unamortized financing costs | (4,000,000) | (5,000,000) | |
| Carrying value of convertible notes | 148,000,000 | 148,000,000 | |
| Interest expense | $ 7,000,000 | $ 3,000,000 | |
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- Definition Debt instrument accrued interest. No definition available.
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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/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 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 of the cost of borrowed funds accounted for as interest expense. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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