Supplemental financial information - Accrued expenses (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Disclosure Text Block Supplement [Abstract]
Accrued capital-related expenditures	$ 352	$ 341
Other	723	570
Total	$ 1,075	$ 911

Obligations not otherwise itemized or categorized in the footnotes to the financial statements that are due within one year or operating cycle, if longer, from the balance sheet date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(20))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 45
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481573/470-10-45-10

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