Fair value measurement (Details) $ in Millions	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)
Minimum | Measurement input, discount rate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Redeemable noncontrolling interest, measurement input	0.0623
Maximum | Measurement input, discount rate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Redeemable noncontrolling interest, measurement input	0.0716
Carrying value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt instrument, fair value disclosure	$ 13,737	$ 11,535	$ 11,222
Fair value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt instrument, fair value disclosure	$ 13,599	$ 11,337	$ 10,471