Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 28, 2019	Dec. 28, 2018
Disaggregation of Revenue [Line Items]
Deferred revenues	$ 1,232	$ 1,496
Refund liability	309
Right to recover product	$ 194
Maximum amortization period, capitalized contract costs	1 year
Minimum
Disaggregation of Revenue [Line Items]
Payment term for contracts with customers	20 days
Maximum
Disaggregation of Revenue [Line Items]
Payment term for contracts with customers	60 days