Other (Income) Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Sep. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Component of Other Income / Expense of Nonoperating [Line Items]
Interest income		$ (9)	$ (14)	$ (20)	$ (39)
Interest expense		202	209	401	421
Exchange losses		114	24	155	78
Income from investments in equity securities, net		(280)	(551)	(854)	(603)
Net periodic defined benefit plan (credit) cost other than service cost		(110)	(80)	(199)	(170)
Other, net		(20)	25	(41)	(12)
Other (income) expense, net		(103)	(387)	(558)	(325)
Unrealized net losses (gains)		$ (18)	$ 464	$ (199)	$ 469
Forecast
Component of Other Income / Expense of Nonoperating [Line Items]
Unrealized net losses (gains)	$ 380

[Line Items] for Component of Other Income / Expense of Nonoperating [Table]

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Other nonoperating income and expense items not separately disclosed.

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Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of unrealized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

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Amount of expense (reversal of expense) for net periodic benefit cost components, excluding service cost component, of defined benefit plan. Amount includes, but is not limited to, interest cost, expected (return) loss on plan asset, amortization of prior service cost (credit), amortization of (gain) loss, amortization of transition (asset) obligation, settlement (gain) loss, curtailment (gain) loss and certain termination benefits.

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