Defined Contribution Plan - Additional Information (Detail)	12 Months Ended
Dec. 31, 2018
Compensation And Retirement Disclosure [Abstract]
Employees may contribute their pay to the Plan	75.00%

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

No definition available.

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration