Goodwill and intangible assets - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible asset amortization expense	$ 288	$ 278
Estimated amortization expense, year ending June 30, 2026	585
Estimated amortization expense, year ending June 30, 2027	586
Estimated amortization expense, year ending June 30, 2028	578
Estimated amortization expense, year ending June 30, 2029	557
Estimated amortization expense, year ending June 30, 2030	$ 528