Retirement Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Contribution by company	$ 0.6	$ 0.2
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's matching contribution, percentage of employee deferrals	5.75%

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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Balance Type:	na
Period Type:	duration