Balance Sheet Components - Change in deferred revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 03, 2020	Sep. 28, 2019	Sep. 29, 2018
Contract with Customer, Liability [Roll Forward]
Deferred revenue, beginning of period	$ 56,449	$ 50,967	$ 45,567
Recognition of revenue included in beginning of period deferred revenue	(13,052)	(11,934)	(10,627)
Revenue deferred, net of revenue recognized on contracts in the respective period	18,992	17,416	16,027
Deferred revenue, end of period	$ 62,389	$ 56,449	$ 50,967