Other Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Deferred rent, less current portion	$ 2,157	$ 3,050
Other long-term obligations	2,414	2,419
Total other liabilities	4,571	5,469
Deferred liability related to sublease execution	400	600
Silicon Valley Bank \| Secured Debt \| Loan and Security Agreement
Debt Instrument [Line Items]
Fee amount on term loan	$ 1,400	$ 1,400

Amount of the fee that accompanies borrowing money under the debt instrument.

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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.

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- Definition

For a classified balance sheet, the cumulative difference between the rental income or payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense, by the lessor or lessee, respectively, more than one year after the balance sheet date.

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This element represents revenue received, but not recognized for financial reporting purposes, which is anticipated to be recognized for financial reporting purposes more than one year from the reporting date or one operating cycle, if longer. Such deferred revenue may consist of and include amounts paid in advance by lessees and purchase price adjustments for leases acquired in a business combination or other transaction.

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Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.

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- Definition

The aggregate carrying amount, as of the balance sheets date, of obligations not otherwise itemized or categorized in the footnotes to the financial statements.

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