Balance Sheet Components - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ (17,436)	$ (9,510)
Total intangible assets, net	23,620
Intangible Assets, Gross	41,056	31,866
Intangible assets, net	23,620	22,356
Amortization of intangible assets	7,926	5,722	$ 2,087
Developed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	35,988	30,588
Accumulated Amortization	(15,983)	(8,738)
Total intangible assets, net	20,005	21,850
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	3,790	0
Accumulated Amortization	(451)	0
Total intangible assets, net	3,339	0
Trademarks and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	1,278	1,278
Accumulated Amortization	(1,002)	(772)
Total intangible assets, net	$ 276	$ 506