Business realignment - Schedule of Business Realignment Charges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2025	Dec. 31, 2024
Cost of sales
Restructuring Cost and Reserve [Line Items]
Business realignment charges	$ 8	$ 12	$ 17	$ 17
Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Business realignment charges	5	9	11	13
Other income, net
Restructuring Cost and Reserve [Line Items]
Business realignment charges	$ 0	$ 0	$ 0	$ 1