Employee Benefit Plan - Additional Information (Details)	3 Months Ended	12 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Compensation And Retirement Disclosure [Abstract]
Maximum employee contribution to plan	100.00%	100.00%

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