401(k) Plan - Additional Information (Detail) - 401(k) plan [Member] $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($)
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution of employee contribution, percent	50.00%
Employer matching contribution, percent	6.00%
Employer discretionary contribution amount	$ 0.6

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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