Retirement Plans - Schedule of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022
Other retirement plans expense (income):
MTM net loss				$ 260
Pension Plans [Member] | U.S. Plans [Member]
Net Periodic Benefit Cost
Service cost	$ 162	$ 209	$ 488	625
Other retirement plans expense (income):
Interest cost	304	254	913	765
Expected return on plan assets	(422)	(478)	(1,266)	(1,433)
Amortization of prior service credit and other	(1)	(1)	(5)	(5)
MTM net loss				36
Other retirement plans (income) expense	(119)	(225)	(358)	(637)
Net periodic benefit cost	43	(16)	130	(12)
Pension Plans [Member] | International Pension Plans [Member]
Net Periodic Benefit Cost
Service cost	13	14	34	43
Other retirement plans expense (income):
Interest cost	8	8	25	27
Expected return on plan assets	(3)	(3)	(11)	(23)
Amortization of prior service credit and other	(2)	(1)	(2)	(2)
MTM net loss				224
Other retirement plans (income) expense	3	4	12	226
Net periodic benefit cost	16	18	46	269
Postretirement Healthcare Plans [Member]
Net Periodic Benefit Cost
Service cost	10	12	28	36
Other retirement plans expense (income):
Interest cost	14	10	42	31
Other retirement plans (income) expense	14	10	42	31
Net periodic benefit cost	$ 24	$ 22	$ 70	$ 67