Fair value measurement (Details) $ in Millions	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)
Minimum | Measurement input, discount rate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Redeemable noncontrolling interest, measurement input	0.0654
Maximum | Measurement input, discount rate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Redeemable noncontrolling interest, measurement input	0.0747
Carrying value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt instrument, fair value disclosure	$ 12,554	$ 11,535	$ 9,678
Fair value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt instrument, fair value disclosure	$ 12,244	$ 11,337	$ 9,159