CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
Statement of Cash Flows [Abstract]
Cash and cash equivalents, beginning of the period	$ 20,289	$ 20,484
Operating activities:
Net income	33,887	28,920
Adjustments to reconcile net income to cash generated by operating activities:
Depreciation and amortization	5,484	5,319
Share-based compensation expense	2,644	2,473
Deferred income tax expense/(benefit)	(34,235)	2,822
Other	(151)	(209)
Changes in operating assets and liabilities:
Accounts receivable, net	3,523	4,183
Inventories	(2,807)	(778)
Vendor non-trade receivables	9,715	4,512
Other current and non-current assets	(1,053)	(896)
Accounts payable	(13,220)	(6,862)
Deferred revenue	478	(221)
Other current and non-current liabilities	39,158	541
Cash generated by operating activities	43,423	39,804
Investing activities:
Purchases of marketable securities	(48,449)	(99,821)
Proceeds from maturities of marketable securities	31,884	12,429
Proceeds from sales of marketable securities	38,942	60,454
Payments for acquisition of property, plant and equipment	(7,005)	(6,309)
Payments made in connection with business acquisitions, net	(305)	(67)
Other	53	(10)
Cash generated by/(used in) investing activities	15,120	(33,324)
Financing activities:
Proceeds from issuance of common stock	327	273
Payments for taxes related to net share settlement of equity awards	(1,190)	(788)
Payments for dividends and dividend equivalents	(6,529)	(6,134)
Repurchases of common stock	(32,851)	(18,012)
Proceeds from issuance of term debt, net	6,969	10,975
Repayments of term debt	(500)	0
Change in commercial paper, net	1	1,879
Cash used in financing activities	(33,773)	(11,807)
Increase/(Decrease) in cash and cash equivalents	24,770	(5,327)
Cash and cash equivalents, end of the period	45,059	15,157
Supplemental cash flow disclosure:
Cash paid for income taxes, net	6,340	6,878
Cash paid for interest	$ 1,356	$ 1,007