Valuation of debt and equity investments and certain liabilities - Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit losses related to available-for-sale investments			$ 0	$ 0
Proceeds from sales, redemptions and maturities of short-term available-for-sale investments	$ 1,260,000,000	$ 2,700,000,000	5,200,000,000	$ 8,460,000,000
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value	0		0		$ 0
Liabilities, fair value	$ 0		$ 0		$ 0

Fair value portion of asset recognized for present right to economic benefit.

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Amount of increase (decrease) in allowance for credit loss of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Fair value of financial and nonfinancial obligations.

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Amount of cash inflow from sale, maturity, prepayment and call of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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