Summary of significant accounting policies - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2023 segment	Dec. 31, 2023 USD ($) segment	Dec. 31, 2023 USD ($) segment division	Dec. 31, 2022 USD ($)
Variable Interest Entity [Line Items]
Number of divisions | division			2
Number of reportable segments | segment	3	4	4
Restricted cash		$ 6	$ 6	$ 5
Designated as hedging instrument | Fair value hedging
Variable Interest Entity [Line Items]
Derivative, notional amount		1,375	1,375	1,775
Designated as hedging instrument | Cash flow hedging
Variable Interest Entity [Line Items]
Derivative, notional amount		550	550	683
Designated as hedging instrument | Net investment hedging
Variable Interest Entity [Line Items]
Derivative, notional amount		1,187	1,187	1,145
Not designated as hedging instrument
Variable Interest Entity [Line Items]
Derivative, notional amount		$ 338	$ 338	$ 280
Minimum | Customer-related
Variable Interest Entity [Line Items]
Finite-lived intangible asset, useful life		5 years	5 years
Minimum | Marketing-related
Variable Interest Entity [Line Items]
Finite-lived intangible asset, useful life		10 years	10 years
Maximum | Customer-related
Variable Interest Entity [Line Items]
Finite-lived intangible asset, useful life		20 years	20 years
Maximum | Marketing-related
Variable Interest Entity [Line Items]
Finite-lived intangible asset, useful life		30 years	30 years
Building
Variable Interest Entity [Line Items]
Property, plant and equipment, useful life		40 years	40 years
Plant and machinery | Minimum
Variable Interest Entity [Line Items]
Property, plant and equipment, useful life		5 years	5 years
Plant and machinery | Maximum
Variable Interest Entity [Line Items]
Property, plant and equipment, useful life		30 years	30 years