Fair value measurement (Details) $ in Millions	Mar. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Mar. 31, 2024 USD ($)
Minimum | Measurement input, discount rate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Redeemable noncontrolling interest, measurement input	0.0647
Maximum | Measurement input, discount rate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Redeemable noncontrolling interest, measurement input	0.0749
Carrying value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt instrument, fair value disclosure	$ 15,578	$ 13,851	$ 12,554
Fair value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt instrument, fair value disclosure	$ 15,342	$ 13,604	$ 12,244