Segment Information and Geographic Data - Net Sales (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 30, 2017	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 64,040	$ 53,809	$ 58,015	$ 84,310	$ 62,900	$ 53,265	$ 61,137	$ 88,293	$ 260,174	$ 265,595	$ 229,234
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									102,266	98,061	84,339
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									43,678	51,942	44,764
Other countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									$ 114,230	$ 115,592	$ 100,131