Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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Weighted average interest rate of short-term debt outstanding calculated at point in time.

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Debt - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Sep. 30, 2017
Debt Instrument [Line Items]
Commercial paper	$ 11,980		$ 11,980		$ 11,977
Commercial paper, general maturity period (less than)			9 months
Commercial paper, weighted-average interest rate	1.68%		1.68%		1.20%
Floating- and fixed-rate notes, aggregate principal amount	$ 111,137		$ 111,137		$ 104,021
Interest expense on term debt	742	$ 507	1,400	$ 1,000
Level 2
Debt Instrument [Line Items]
Floating- and fixed-rate notes, aggregate fair value	111,100		111,100		106,100
Net investment hedges
Debt Instrument [Line Items]
Carrying value of debt designated as a net investment hedge	$ 518		$ 518		$ 1,600