Accumulated Other Comprehensive Loss - Reclassification Out of Accumulated Other Comprehensive Income (Loss) (Details) - Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2022	Nov. 30, 2021
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other retirement plans (expense) income	$ 2	$ 3	$ 4	$ 5
Provision for income taxes	(1)	(1)	(1)	(1)
Net income	$ 1	$ 2	$ 3	$ 4