Employee Benefit Plans - Additional Information (Details) - shares shares in Thousands	1 Months Ended	3 Months Ended
	Jul. 31, 2018	Mar. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined contribution retirement plan, plan name		401(k) plan
2018 ESPP
Defined Benefit Plan Disclosure [Line Items]
Shares of common stock reserved for issuance	200	244	244
Common stock purchase price, discount rate	15.00%
Maximum | 2018 ESPP
Defined Benefit Plan Disclosure [Line Items]
Period of automatic annual increase in the share reserve	10 years
401(k) Plan
Defined Benefit Plan Disclosure [Line Items]
Defined contribution retirement plan, maximum employee contribution deferred		100.00%