RETIREMENT PLANS - Schedule of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended	4 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Pension Plans \| U.S. Plans
Net Periodic Benefit Cost
Service cost	$ 107	$ 108	$ 146	$ 146
Interest cost	384	370	518	490
Expected return on plan assets	(484)	(436)	(637)	(582)
Amortization of prior service cost (credit)	10	(2)	9	(3)
Actuarial losses (gains) and other	0	0	(141)	0
Net periodic benefit (income) cost	17	40	(105)	51
Postretirement Healthcare Plans
Net Periodic Benefit Cost
Service cost	7	7	9	9
Interest cost	16	17	21	22
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	(1)	(1)	(1)	(1)
Actuarial losses (gains) and other	0	0	0	0
Net periodic benefit (income) cost	$ 22	$ 23	$ 29	$ 30

Defined Benefit Plan Amortization Of Gains Losses And Other

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- Definition

Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.

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- Definition

Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of net periodic benefit cost (credit) for defined benefit plan.

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Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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