Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible amortization expense	$ 397	$ 362	$ 1,189	$ 1,092

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets.

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