Fair value measurement - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Aggregate fair value of long-term debt, including current portion	$ 57,800	$ 59,200
Carrying value of long-term debt, including current portion	$ 64,020	$ 64,613

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant