Investments (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized cost	$ 10,921	$ 7,304
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair values	10,921	7,304
U.S. Treasury notes
Debt Securities, Available-for-sale [Line Items]
Amortized cost	0	47
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair values	0	47
U.S. Treasury bills
Debt Securities, Available-for-sale [Line Items]
Amortized cost	1,976	1,400
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair values	1,976	1,400
Money market mutual funds
Debt Securities, Available-for-sale [Line Items]
Amortized cost	8,945	5,856
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair values	8,945	5,856
Other short-term interest-bearing securities
Debt Securities, Available-for-sale [Line Items]
Amortized cost	0	1
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair values	$ 0	$ 1

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on 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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Amortized cost 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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