Supplemental Information - Schedule of Revenues by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	$ 73,309	$ 52,125	$ 248,069
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	46,604	37,802	168,414
EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	22,520	13,874	72,485
Japan
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	3,370	$ 449	6,351
Greater China
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	$ 815		$ 819