Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions		12 Months Ended
		May 31, 2024	May 31, 2023	May 31, 2022
Allowance For Credit Losses [Member]
Movement In Valuation Allowances And Reserves Roll Forward
Valuation Allowances And Reserves Beginning Balance		$ 472	$ 340	$ 358
Charged To Expenses		422	696	403
Deductions	[1]	458	564	421
Valuation Allowances And Reserves Ending Balance		436	472	340
Allowance For Revenue Adjustments [Member]
Movement In Valuation Allowances And Reserves Roll Forward
Valuation Allowances And Reserves Beginning Balance		328	352	384
Charged To Other Accounts	[2]	1,534	1,662	1,795
Deductions	[3]	1,523	1,686	1,827
Valuation Allowances And Reserves Ending Balance		339	328	352
Inventory Valuation Allowance [Member]
Movement In Valuation Allowances And Reserves Roll Forward
Valuation Allowances And Reserves Beginning Balance		276	360	349
Charged To Expenses		40	33	35
Deductions		28	117	24
Valuation Allowances And Reserves Ending Balance		$ 288	$ 276	$ 360

[1] Uncollectible accounts written off, net of recoveries, and other adjustments.

[2] Principally charged against revenue.

[3] Service failures, rebills, and other.