Other Financial Information (PPE) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property, plant and equipment, at cost	$ 9,442	$ 9,427
Less: Accumulated depreciation	5,757	5,689
Total	$ 3,685	$ 3,738

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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