Commitments and Contingencies - Narrative (Details)	1 Months Ended	9 Months Ended
	Oct. 31, 2018	Sep. 30, 2018	Mar. 31, 2019 USD ($)	Feb. 13, 2019 ft²	Dec. 30, 2018 USD ($)
Purchase Commitment Excluding Longterm Commitment [Line Items]
Purchase obligations due within next twelve months			$ 12,000
Operating lease end date	2019-07
Operating lease termination notice period	9 months
Operating lease relating to future lease commitments			2,700,000
Operating lease relating to future lease commitments due within the next twelve months			825,000
Square feet of office space leased | ft²				24,164
Lease period				5 years
San Diego, California | Research and Development centre
Purchase Commitment Excluding Longterm Commitment [Line Items]
Operating lease expiration date	2020-07
Primary facility lease
Purchase Commitment Excluding Longterm Commitment [Line Items]
Operating lease expiration date		2020-03
Wafer and finished goods inventory
Purchase Commitment Excluding Longterm Commitment [Line Items]
Outstanding commitment for purchases			44,000		$ 22,000
Other goods and services
Purchase Commitment Excluding Longterm Commitment [Line Items]
Total outstanding purchase obligations			$ 1,600,000