Marketable Securities and Fair Value Measurements - Financial Assets at Fair Value on Recurring Basis (Detail) - Money Market Funds - USD ($) $ in Thousands |
Mar. 31, 2018 |
Dec. 31, 2017 |
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| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Total cash equivalents and marketable securities | $ 48,830 | $ 51,751 |
| Basis of Fair Value Measurements, Level 1 | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Total cash equivalents and marketable securities | 48,830 | 51,751 |
| Basis of Fair Value Measurements, Level 2 | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Total cash equivalents and marketable securities | 0 | 0 |
| Basis of Fair Value Measurements, Level 3 | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Total cash equivalents and marketable securities | $ 0 | $ 0 |
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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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