Derivative instruments - Fair Value of Derivatives Included in the Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Derivatives Fair Value [Line Items]
Derivative assets	$ 251	$ 341
Derivative liabilities	1,311	1,398
Forward interest rate contracts
Derivatives Fair Value [Line Items]
Derivative liabilities	0	5
Derivatives designated as hedging instrument
Derivatives Fair Value [Line Items]
Derivative assets	251	341
Derivative liabilities	1,311	1,398
Derivatives designated as hedging instrument | Foreign currency forward contracts
Derivatives Fair Value [Line Items]
Derivative assets	251	287
Derivative liabilities	83	76
Derivatives designated as hedging instrument | Cross-currency swap contracts
Derivatives Fair Value [Line Items]
Derivative assets	0	54
Derivative liabilities	493	541
Derivatives designated as hedging instrument | Interest rate swap contracts
Derivatives Fair Value [Line Items]
Derivative assets	0	0
Derivative liabilities	735	776
Derivatives designated as hedging instrument | Forward interest rate contracts
Derivatives Fair Value [Line Items]
Derivative assets	0	0
Derivatives designated as hedging instrument | Forward interest rate contracts
Derivatives Fair Value [Line Items]
Derivative liabilities	$ 0	$ 5