Retirement Plans - Reconciliation of Changes In Pension And Postretirement Healthcare Plans Benefit Obligations And Fair Value Of Assets (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
U.S. Plans [Member]
Change in Plan Assets
Company contributions	$ 500	$ 300
Pension Plans [Member]
Changes in PBO and Accumulated Postretirement Benefit Obligation (“APBO”)
PBO/APBO at the beginning of year	34,034
PBO/APBO at the end of year	29,798	34,034
Change in Plan Assets
Balance at beginning of year	31,918
Balance at end of year	26,633	31,918
Funded Status of the Plans	(3,165)	(2,116)
Pension Plans [Member] | U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated Benefit Obligation (“ABO”)	27,916	30,455
Changes in PBO and Accumulated Postretirement Benefit Obligation (“APBO”)
PBO/APBO at the beginning of year	31,423	30,199
Service cost	835	851	$ 768
Interest cost	1,020	959	1,000
Actuarial (gain) loss	(3,356)	362
Benefits paid	(1,180)	(948)
Other	(40)
PBO/APBO at the end of year	28,702	31,423	30,199
Change in Plan Assets
Balance at beginning of year	29,785	26,978
Actual return on plan assets	(3,168)	3,436
Company contributions	533	319
Benefits paid	(1,180)	(948)
Balance at end of year	25,970	29,785	26,978
Funded Status of the Plans	(2,732)	(1,638)
Amount Recognized in the Balance Sheet at May 31:
Current pension, postretirement healthcare and other benefit obligations	(20)	(41)
Noncurrent pension, postretirement healthcare and other benefit obligations	(2,712)	(1,597)
Net amount recognized	(2,732)	(1,638)
Amounts Recognized in AOCI and not yet reflected in Net Periodic Benefit Cost:
Prior service (credit) cost and other	(54)	(61)
Pension Plans [Member] | International Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated Benefit Obligation (“ABO”)	946	2,417
Changes in PBO and Accumulated Postretirement Benefit Obligation (“APBO”)
PBO/APBO at the beginning of year	2,611	2,242
Service cost	56	83	96
Interest cost	32	43	43
Actuarial (gain) loss	(19)	105
Benefits paid	(36)	(53)
Settlements	(1,315)	(11)
Other	(233)	202
PBO/APBO at the end of year	1,096	2,611	2,242
Change in Plan Assets
Balance at beginning of year	2,133	1,713
Actual return on plan assets	(4)	114
Company contributions	135	142
Benefits paid	(36)	(53)
Settlements	(1,395)	(11)
Other	(170)	228
Balance at end of year	663	2,133	1,713
Funded Status of the Plans	(433)	(478)
Amount Recognized in the Balance Sheet at May 31:
Noncurrent asset	126	231
Current pension, postretirement healthcare and other benefit obligations	(19)	(18)
Noncurrent pension, postretirement healthcare and other benefit obligations	(540)	(691)
Net amount recognized	(433)	(478)
Amounts Recognized in AOCI and not yet reflected in Net Periodic Benefit Cost:
Prior service (credit) cost and other	(3)	(6)
Postretirement Healthcare Plans [Member]
Changes in PBO and Accumulated Postretirement Benefit Obligation (“APBO”)
PBO/APBO at the beginning of year	1,456	1,314
Service cost	48	44	42
Interest cost	41	39	44
Actuarial (gain) loss	(192)	125
Benefits paid	(113)	(112)
Other	46	46
PBO/APBO at the end of year	1,286	1,456	$ 1,314
Change in Plan Assets
Company contributions	68	64
Benefits paid	(113)	(112)
Other	45	48
Funded Status of the Plans	(1,286)	(1,456)
Amount Recognized in the Balance Sheet at May 31:
Current pension, postretirement healthcare and other benefit obligations	(95)	(110)
Noncurrent pension, postretirement healthcare and other benefit obligations	(1,191)	(1,346)
Net amount recognized	$ (1,286)	$ (1,456)