Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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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).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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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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No definition available.

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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).

+ References

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The cash inflow from sales of all investments, including securities and other assets, having ready marketability and intended by management to be liquidated, if necessary, within the current operating cycle. Includes cash flows from securities classified as trading securities that were acquired for reasons other than sale in the short-term.

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Valuation of debt and equity investments and certain liabilities - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
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	$ 1,320,000,000	$ 510,000,000	5,770,000,000	3,710,000,000
Proceeds from sale of short-term investments				$ 253,000,000
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities, fair value	0		0		$ 0
Assets, fair value	$ 0		$ 0		$ 0