Retirement Plans - Schedule of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Pension Plans [Member] | U.S. Plans [Member]
Net Periodic Benefit Cost
Service cost	$ 835	$ 851	$ 768
Interest cost	1,020	959	1,000
Expected return on plan assets	(1,910)	(1,786)	(1,601)
Amortization of prior service credit	(7)	(8)	(105)
Actuarial (gains) losses and other	1,683	(1,288)	888
Net periodic benefit cost	1,621	(1,272)	950
Pension Plans [Member] | International Pension Plans [Member]
Net Periodic Benefit Cost
Service cost	56	83	96
Interest cost	32	43	43
Expected return on plan assets	(26)	(52)	(51)
Amortization of prior service credit	(2)	(2)	(2)
Actuarial (gains) losses and other	87	(13)	(179)
Net periodic benefit cost	147	59	(93)
Postretirement Healthcare Plans [Member]
Net Periodic Benefit Cost
Service cost	48	44	42
Interest cost	41	39	44
Actuarial (gains) losses and other	(192)	125	85
Net periodic benefit cost	$ (103)	$ 208	$ 171