Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2016	Sep. 27, 2015	Oct. 02, 2016	Sep. 27, 2015	Jan. 03, 2016
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Capital lease maintenance commitment	$ 2		$ 2
Total rent expense, net of sublease income	219	$ 201	623	$ 678
Wafer and finished goods inventory
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Outstanding commitment for purchases	2,700		2,700		$ 1,400
Other goods and services
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Total outstanding purchase obligations	$ 1,100		$ 1,100