Commitments and Contingencies - Narrative (Details) - USD ($)	1 Months Ended	12 Months Ended
	May 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Feb. 28, 2018	Aug. 31, 2012
Operating Leased Assets [Line Items]
Rent expense		$ 1,200,000	$ 1,000,000
Purchase commitments related to inventory		200,000	$ 100,000
San Jose, California
Operating Leased Assets [Line Items]
Non-cancelable operating lease term					4 years
Early termination fees	$ 0
Santa Clara, California
Operating Leased Assets [Line Items]
Non-cancelable operating lease term				7 years
Indemnification Agreement
Operating Leased Assets [Line Items]
Costs to defend lawsuits or settle claims		0
Costs accrued to defend lawsuits		$ 0