Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 24, 2016	Sep. 26, 2015
Federal:
Current	$ 7,842	$ 7,652	$ 11,730
Deferred	5,980	5,043	3,408
Federal income tax expense (benefit)	13,822	12,695	15,138
State:
Current	259	990	1,265
Deferred	2	(138)	(220)
State income tax expense (benefits)	261	852	1,045
Foreign:
Current	1,671	2,105	4,744
Deferred	(16)	33	(1,806)
Foreign income tax expense (benefit)	1,655	2,138	2,938
Provision for income taxes	15,738	15,685	19,121
Federal income taxes provided on foreign pre-tax earnings	$ 7,900	$ 6,700	$ 7,300