Goodwill and intangible assets - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible asset amortization expense	$ 140	$ 140
Estimated amortization expense, year ending June 30, 2026	584
Estimated amortization expense, year ending June 30, 2027	587
Estimated amortization expense, year ending June 30, 2028	578
Estimated amortization expense, year ending June 30, 2029	558
Estimated amortization expense, year ending June 30, 2030	$ 529