Accrued Expenses - Components of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Components of accrued expenses
Customer deposits	$ 496	$ 336
Earn-out – short term	305	370
Distributor commission	171	234
Sales and use tax payable	94	105
Royalties payable	66	52
Other accrued expenses	1,003	625
Total accrued expenses	$ 2,135	$ 1,722