Retirement Plans - Schedule of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2022	Aug. 31, 2021
Pension Plans [Member] | U.S. Plans [Member]
Net Periodic Benefit Cost
Service cost	$ 163	$ 208
Other retirement plans expense (income):
Interest cost	304	256
Expected return on plan assets	(422)	(478)
Amortization of prior service credit and other	(2)	(2)
Other retirement plans (income) expense	(120)	(224)
Net periodic benefit cost	43	(16)
Pension Plans [Member] | International Pension Plans [Member]
Net Periodic Benefit Cost
Service cost	11	15
Other retirement plans expense (income):
Interest cost	9	12
Expected return on plan assets	(4)	(14)
Other retirement plans (income) expense	5	(2)
Net periodic benefit cost	16	13
Postretirement Healthcare Plans [Member]
Net Periodic Benefit Cost
Service cost	9	12
Other retirement plans expense (income):
Interest cost	14	10
Other retirement plans (income) expense	14	10
Net periodic benefit cost	$ 23	$ 22