CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 24, 2016	Sep. 26, 2015
Statement of Cash Flows [Abstract]
Cash and cash equivalents, beginning of the year	$ 20,484	$ 21,120	$ 13,844
Operating activities:
Net income	48,351	45,687	53,394
Adjustments to reconcile net income to cash generated by operating activities:
Depreciation and amortization	10,157	10,505	11,257
Share-based compensation expense	4,840	4,210	3,586
Deferred income tax expense	5,966	4,938	1,382
Other	(166)	486	385
Changes in operating assets and liabilities:
Accounts receivable, net	(2,093)	527	417
Inventories	(2,723)	217	(238)
Vendor non-trade receivables	(4,254)	(51)	(3,735)
Other current and non-current assets	(5,318)	1,055	(283)
Accounts payable	9,618	1,837	5,001
Deferred revenue	(626)	(1,554)	1,042
Other current and non-current liabilities	(154)	(2,033)	9,058
Cash generated by operating activities	63,598	65,824	81,266
Investing activities:
Purchases of marketable securities	(159,486)	(142,428)	(166,402)
Proceeds from maturities of marketable securities	31,775	21,258	14,538
Proceeds from sales of marketable securities	94,564	90,536	107,447
Payments made in connection with business acquisitions, net	(329)	(297)	(343)
Payments for acquisition of property, plant and equipment	(12,451)	(12,734)	(11,247)
Payments for acquisition of intangible assets	(344)	(814)	(241)
Payments for strategic investments, net	(395)	(1,388)	0
Other	220	(110)	(26)
Cash used in investing activities	(46,446)	(45,977)	(56,274)
Financing activities:
Proceeds from issuance of common stock	555	495	543
Excess tax benefits from equity awards	627	407	749
Payments for taxes related to net share settlement of equity awards	(1,874)	(1,570)	(1,499)
Payments for dividends and dividend equivalents	12,769	12,150	11,561
Repurchases of common stock	(32,900)	(29,722)	(35,253)
Proceeds from issuance of term debt, net	28,662	24,954	27,114
Repayments of term debt	(3,500)	(2,500)	0
Change in commercial paper, net	3,852	(397)	2,191
Cash used in financing activities	(17,347)	(20,483)	(17,716)
Increase/(Decrease) in cash and cash equivalents	(195)	(636)	7,276
Cash and cash equivalents, end of the year	20,289	20,484	21,120
Supplemental cash flow disclosure:
Cash paid for income taxes, net	11,591	10,444	13,252
Cash paid for interest	$ 2,092	$ 1,316	$ 514