Supplemental Information - Schedule of Revenues by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	$ 64,756	$ 50,109	$ 178,395	$ 123,365	$ 177,026
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	44,469	35,300	124,206	95,826	134,688
EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	18,295	14,757	50,692	27,316	42,035
Japan
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	$ 1,992	$ 52	$ 3,497	$ 223	$ 303