Commitments and Contingencies - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Oct. 01, 2016 USD ($)	Sep. 26, 2015 USD ($)	Oct. 01, 2016 USD ($) Renewals	Sep. 26, 2015 USD ($)	Jul. 02, 2016 USD ($)
Other Commitments [Line Items]
Accrued expense on operating lease renewal					$ 184,000
Rent expense	$ 173,000	$ 167,000	$ 492,000	$ 357,000
Percentage of minimum royalty payment			0.13%
Percentage of maximum royalty payment			2.50%
Royalty expense	$ 11,000	$ 11,000	$ 34,000	$ 31,000
Minimum [Member]
Other Commitments [Line Items]
Royalty obligations termination period			2016
Maximum [Member]
Other Commitments [Line Items]
Royalty obligations termination period			2020
Santa Barbara [Member]
Other Commitments [Line Items]
Lease facility expires			2016-11
Renewal period of operating lease			5 years
Number of five-year renewal option | Renewals			1
Austin, Texas [Member]
Other Commitments [Line Items]
Lease facility expires			2017-03
Renewal period of operating lease			5 years
Number of five-year renewal option | Renewals			1