Retirement Plans - Schedule of Net Periodic Benefit (Income) Cost (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2023	May 31, 2022	May 31, 2021
Pension Plans [Member] | U.S. Plans [Member]
Net Periodic Benefit Cost
Service cost	$ 651	$ 835	$ 851
Interest cost	1,218	1,020	959
Expected return on plan assets	(1,688)	(1,910)	(1,786)
Amortization of prior service credit	(7)	(7)	(8)
Actuarial (gains) losses and other	(487)	1,683	(1,288)
Net periodic benefit (income) cost	(313)	1,621	(1,272)
Pension Plans [Member] | International Pension Plans [Member]
Net Periodic Benefit Cost
Service cost	44	56	83
Interest cost	34	32	43
Expected return on plan assets	(14)	(26)	(52)
Amortization of prior service credit	(2)	(2)	(2)
Actuarial (gains) losses and other	(25)	87	(13)
Net periodic benefit (income) cost	37	147	59
Postretirement Healthcare Plans [Member]
Net Periodic Benefit Cost
Service cost	37	48	44
Interest cost	55	41	39
Actuarial (gains) losses and other	(138)	(192)	125
Net periodic benefit (income) cost	$ (46)	$ (103)	$ 208