Accounts receivable, net - Summary of accounts receivable (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 6,598	$ 4,519	$ 6,110
Less: allowance for credit losses	(158)	(140)	(151)
Other current receivables	521	441	463
Total accounts receivable, net	6,961	4,820	6,422
Trade receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	5,641	3,829	5,106
Construction contract assets
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 957	$ 690	$ 1,004