Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions		12 Months Ended
		May 31, 2022	May 31, 2021	May 31, 2020
Allowance For Doubtful Accounts [Member]
Movement In Valuation Allowances And Reserves Roll Forward
Valuation Allowances And Reserves Beginning Balance		$ 358	$ 175	$ 121
Charged To Expenses		403	577	442
Deductions	[1]	421	394	388
Valuation Allowances And Reserves Ending Balance		340	358	175
Allowance For Revenue Adjustments [Member]
Movement In Valuation Allowances And Reserves Roll Forward
Valuation Allowances And Reserves Beginning Balance		384	215	179
Charged To Other Accounts	[2]	1,795	1,892	1,286
Deductions	[3]	1,827	1,723	1,250
Valuation Allowances And Reserves Ending Balance		352	384	215
Inventory Valuation Allowance [Member]
Movement In Valuation Allowances And Reserves Roll Forward
Valuation Allowances And Reserves Beginning Balance		349	335	335
Charged To Expenses		35	38	33
Deductions		24	24	33
Valuation Allowances And Reserves Ending Balance		$ 360	$ 349	$ 335

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

[2] Principally charged against revenue.

[3] Service failures, rebills, and other.