Financial Instruments - Pre-Tax Gains and Losses of Derivative and Non-Derivative Instruments Designated as Hedges (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 30, 2019	Mar. 31, 2018	Mar. 30, 2019	Mar. 31, 2018
Cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) recognized in OCI – effective portion	$ (64)	$ 37	$ (542)	$ 191
Gains/(Losses) reclassified from AOCI into net income – effective portion	132	289	13	166
Cash flow hedges \| Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) recognized in OCI – effective portion	(64)	37	(542)	190
Gains/(Losses) reclassified from AOCI into net income – effective portion	134	287	16	163
Cash flow hedges \| Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) recognized in OCI – effective portion	0	0	0	1
Gains/(Losses) reclassified from AOCI into net income – effective portion	(2)	2	(3)	3
Net investment hedges \| Foreign currency debt
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) recognized in OCI – effective portion	(7)	(33)	(23)	(31)
Fair value hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) on derivative instruments designated as fair value hedges	708	(674)	1,767	(948)
Gains/(Losses) related to hedged items in fair value hedges	(707)	674	(1,766)	948
Fair value hedges \| Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) on derivative instruments designated as fair value hedges	243	0	645	0
Gains/(Losses) related to hedged items in fair value hedges	(242)	0	(644)	0
Fair value hedges \| Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) on derivative instruments designated as fair value hedges	465	(674)	1,122	(948)
Gains/(Losses) related to hedged items in fair value hedges	$ (465)	$ 674	$ (1,122)	$ 948

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 25
-Section 50
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- Definition

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

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-Publisher FASB
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- Definition

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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