Other income, net - Schedule of Components of Other Income, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2025	Dec. 31, 2024
Other Income and Expenses [Abstract]
Foreign currency transaction (gain) loss	$ (3)	$ (32)	$ (10)	$ 5
Income related to equity method investments	(51)	(39)	(109)	(77)
Non-service components of retirement benefit cost (income)	(16)	(13)	(33)	(25)
Gain on disposal of assets and divestitures	(9)	(248)	(8)	(257)
Interest income	(2)	(2)	(7)	(5)
Gain on insurance recoveries	0	0	(20)	0
Other items, net	5	6	4	0
Total other income, net	$ (76)	$ (328)	$ (183)	$ (359)