Fair Value - Narrative (Details) - USD ($) |
Sep. 30, 2017 |
Dec. 31, 2016 |
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| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Total assets measured at fair value | $ 6,249,000 | $ 43,361,000 |
| Money market funds | Fair value measured on a recurring basis | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair value | 87,500,000 | 55,800,000 |
| Level 3 | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Total assets measured at fair value | 0 | 0 |
| Liabilities measured at fair value | $ 0 | $ 0 |
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- Definition Fair value of investment in certain entities that calculate net asset value per share. Includes, but is not limited to, by unit, membership interest, or other ownership interest. Investment includes, but is not limited to, investment in certain hedge funds, venture capital funds, private equity funds, real estate partnerships or funds. Excludes measurement of net asset value as estimate of fair value. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a recurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. No definition available.
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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 Aggregation of the liabilities reported on the balance sheet measured at fair value on a recurring basis by the entity. No definition available.
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