Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 02, 2020	Jun. 26, 2020	Mar. 27, 2020	Dec. 27, 2019	Sep. 27, 2019	Jun. 28, 2019	Mar. 29, 2019	Dec. 28, 2018	Oct. 02, 2020	Sep. 27, 2019	Sep. 28, 2018
Selected Quarterly Financial Information [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 956,800	$ 736,800	$ 766,100	$ 896,100	$ 827,400	$ 767,000	$ 810,400	$ 972,000	$ 3,355,700	$ 3,376,800	$ 3,868,000
Gross Profit	458,900	334,100	375,600	444,300	406,000	312,500	400,200	485,100	1,612,900	1,603,800	1,950,700
Net income	$ 246,900	$ 129,700	$ 181,100	$ 257,100	$ 210,600	$ 144,100	$ 214,000	$ 284,900	$ 814,800	$ 853,600	$ 918,400
Net income, basic (in dollars per share)	$ 1.48	$ 0.78	$ 1.07	$ 1.51	$ 1.23	$ 0.83	$ 1.23	$ 1.61	$ 4.84	$ 4.92	$ 5.06
Net income, diluted (in dollars per share)	$ 1.46	$ 0.77	$ 1.06	$ 1.50	$ 1.22	$ 0.83	$ 1.23	$ 1.60	$ 4.80	$ 4.89	$ 5.01