Financial Instruments - Pre-Tax Gains and Losses of Derivative and Non-Derivative Instruments Designated as Hedges (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) recognized in OCI – effective portion	$ (147)	$ 40	$ (689)	$ 231
Gains/(Losses) reclassified from AOCI into net income – effective portion	51	(1,231)	64	(1,065)
Cash flow hedges \| Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) recognized in OCI – effective portion	(147)	40	(689)	230
Gains/(Losses) reclassified from AOCI into net income – effective portion	53	(1,231)	69	(1,068)
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)	0	(5)	3
Net investment hedges \| Foreign currency debt
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) recognized in OCI – effective portion	(32)	13	(55)	(18)
Fair value hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) on derivative instruments designated as fair value hedges	535	(199)	2,302	(1,147)
Gains/(Losses) related to hedged items in fair value hedges	(535)	199	(2,301)	1,147
Fair value hedges \| Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) on derivative instruments designated as fair value hedges	(136)	31	509	31
Gains/(Losses) related to hedged items in fair value hedges	136	(31)	(508)	(31)
Fair value hedges \| Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses) on derivative instruments designated as fair value hedges	671	(230)	1,793	(1,178)
Gains/(Losses) related to hedged items in fair value hedges	$ (671)	$ 230	$ (1,793)	$ 1,178

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
-Topic 815
-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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
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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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-Publisher FASB
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