Comprehensive Income - Pre-tax Amounts Reclassified from AOCI into Consolidated Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 26, 2015	Sep. 30, 2017	Sep. 24, 2016	Sep. 26, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenue	$ (52,579)	$ (45,408)	$ (52,896)	$ (78,351)	$ (46,852)	$ (42,358)	$ (50,557)	$ (75,872)	$ (229,234)	$ (215,639)	$ (233,715)
Cost of sales									141,048	131,376	140,089
Other income/(expense), net									(2,745)	(1,348)	(1,285)
Total amounts reclassified from AOCI									(64,089)	(61,372)	$ (72,515)
Reclassifications out of AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total amounts reclassified from AOCI									(2,051)	(785)
Reclassifications out of AOCI | Unrealized (gains)/losses on derivative instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total amounts reclassified from AOCI									(1,952)	(872)
Reclassifications out of AOCI | Unrealized (gains)/losses on derivative instruments | Foreign exchange contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenue									(662)	(865)
Cost of sales									(654)	(130)
Other income/(expense), net									(638)	111
Reclassifications out of AOCI | Unrealized (gains)/losses on derivative instruments | Interest rate contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income/(expense), net									2	12
Reclassifications out of AOCI | Unrealized (gains)/losses on marketable securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income/(expense), net									$ (99)	$ 87