Revenue recognition - Schedule of Total Revenue by Geographic Region (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Revenues from contracts	$ 19,850	$ 19,930	$ 19,065
North America
Disaggregation of Revenue [Line Items]
Revenues from contracts	13,406	13,512	12,690
Europe
Disaggregation of Revenue [Line Items]
Revenues from contracts	3,862	3,916	3,778
Asia Pacific
Disaggregation of Revenue [Line Items]
Revenues from contracts	2,364	2,278	2,380
Latin America
Disaggregation of Revenue [Line Items]
Revenues from contracts	$ 218	$ 224	$ 217