Employee Benefit Plan - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Employee contribution to retirement saving plan as a percentage of annual salary, maximum	60.00%
Matching contributions made by the entity during the period	$ 2,833	$ 2,212	$ 1,944
Percentage of company's matching contributions of first 3 percent of employee's compensation	100.00%
Percentage of employee's compensation that qualifies for 100 percent matching contribution by the company	3.00%
Maximum percentage of the company's matching contributions of next 2 percent of employee's compensation	50.00%
Percentage of employee's compensation that qualifies for 50 percent matching contribution by the company	2.00%