Retirement Plans - Schedule of Components of Pension Plans (Details) - Pension Plans [Member] - USD ($) $ in Millions	May 31, 2020	May 31, 2019	May 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation ("PBO")	$ 32,441	$ 28,855
Fair Value of Plan Assets	28,691	24,898
Funded Status	(3,750)	(3,957)
Qualified [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation ("PBO")	30,004	26,300
Fair Value of Plan Assets	26,978	23,320
Funded Status	(3,026)	(2,980)
Nonqualified [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation ("PBO")	195	254
Funded Status	(195)	(254)
International Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation ("PBO")	2,242	2,301	$ 2,167
Fair Value of Plan Assets	1,713	1,578	$ 1,509
Funded Status	$ (529)	$ (723)

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

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+ References

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Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

+ References

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Amount of funded (unfunded) status of defined benefit plan, measured as difference between fair value of plan assets and benefit obligation. Includes, but is not limited to, overfunded (underfunded) status.

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