Variable interest entities - Schedule of results of variable interest entities (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Variable Interest Entity [Line Items]
Gross profit	$ 4,294	$ 4,026	$ 6,339	$ 5,863
Net loss	1,486	1,319	1,310	1,225
Net cash used in operating activities			513	719
Variable interest entity, primary beneficiary
Variable Interest Entity [Line Items]
Total revenues	73	82	147	166
Total cost of revenues	(69)	(85)	(153)	(165)
Gross profit	4	(3)	(6)	1
Net loss	$ (5)	$ (17)	(28)	(30)
Net cash used in operating activities			$ (35)	$ (12)

The aggregate cost of goods produced and sold and services rendered during the reporting period.

- Definition

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

+ References

+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

+ Details