Commitments and Contingencies - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Other Commitments [Line Items]
Rent expense	$ 300,000	$ 300,000	$ 900,000	$ 900,000
Purchase commitments related to inventory	300,000		300,000		$ 200,000
Accrued litigation expense	2,500,000		2,500,000		$ 0
Indemnification Agreement
Other Commitments [Line Items]
Costs to defend lawsuits or settle claims			0
Costs accrued to defend lawsuits	$ 0		$ 0
Santa Clara, California
Other Commitments [Line Items]
Non-cancelable operating lease term	7 years		7 years