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Retirement Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Retirement plan, employees maximum pre-tax contributions percentage	60.00%
Contributions to 401(k) plan	$ 0	$ 0	$ 0
401 (K) Plan
Defined Benefit Plan Disclosure [Line Items]
Retirement plan, employees maximum pre-tax contributions percentage	6.00%
Employer matching contribution, percent of employee's contribution	50.00%
Maximum annual contributions per employee, amount	$ 5,000

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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.

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- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

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- Definition

Percentage employer matches of the employee's percentage contribution matched.

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- Definition

Maximum amount the employee may contribute to a defined contribution plan.

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

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