Balance Sheet Details - Allowance for credit losses (Details) $ in Thousands	6 Months Ended
	Jun. 27, 2020 USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of December 28, 2019	$ 4,005
Additions	962
Write offs	(2,418)
Recoveries during the period	(39)
Other	23
Balance as of June 27, 2020	3,183
Cumulative Effect, Period of Adoption, Adjustment
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of December 28, 2019	$ 650