Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Current:
Federal	$ 499	$ 536	$ 508
State	45	38	30
Foreign	1,345	1,869	304
Current income tax (provision) benefit	1,889	2,443	842
Deferred:
Federal	0	0	0
State	0	0	0
Foreign	(317)	(90)	7
Deferred income tax (provision) benefit	(317)	(90)	7
Income tax expense	$ 1,572	$ 2,353	$ 849