Income Taxes - Provisions for Income Taxes Computed by Applying Statutory Federal Income Tax Rates (Details)	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Income Tax Disclosure [Abstract]
Expected tax at federal statutory rate	21.00%	21.00%	35.00%
State taxes, net of federal benefit	(0.10%)	(0.10%)	0.00%
Research credits	1.00%	1.80%	1.80%
Stock-based compensation	(2.00%)	(0.80%)	(6.00%)
Change in valuation allowance	(19.70%)	(18.10%)	(26.80%)
Foreign rate differential	(0.20%)	(2.90%)	(3.30%)
Other	(0.80%)	(0.60%)	0.00%
Effective tax rate	(0.80%)	0.30%	0.70%