Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 03, 2020	Jun. 27, 2020	Mar. 28, 2020	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Oct. 03, 2020	Sep. 28, 2019	Sep. 29, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 339,837	$ 249,310	$ 175,098	$ 562,083	$ 294,160	$ 260,119	$ 210,173	$ 496,371	$ 1,326,328	$ 1,260,823	$ 1,137,008
Gross profit	161,536	109,791	73,009	227,620	124,271	117,370	90,413	195,289	571,956	527,343	489,308
Net income (loss)	$ 18,411	$ (56,980)	$ (52,320)	$ 70,775	$ (29,600)	$ (14,009)	$ (22,824)	$ 61,667	$ (20,115)	$ (4,766)	$ (15,604)
Net income (loss) per share - basic (in dollars per share)	$ 0.17	$ (0.52)	$ (0.48)	$ 0.65	$ (0.28)	$ (0.13)	$ (0.22)	$ 0.62
Net income (loss) per share - diluted (in dollars per share)	$ 0.15	$ (0.52)	$ (0.48)	$ 0.60	$ (0.28)	$ (0.13)	$ (0.22)	$ 0.55