Balance Sheet Components - Schedule of Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 26, 2020	Dec. 31, 2019
Other Liabilities Noncurrent [Abstract]
Unrecognized tax benefits (including interest)	$ 3,812	$ 6,384
Non-current operating lease obligations	$ 16,455	$ 19,970
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	onto:OperatingLeaseLiabilityNonCurrentMember	onto:OperatingLeaseLiabilityNonCurrentMember
Deferred revenue	$ 1,292	$ 2,464
Other	6,153	2,953
Total non-current liabilities	$ 27,712	$ 31,771