Investments - Schedule of Available-For-Sale Investments (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Marketable Securities [Line Items]
Amortized cost	$ 8,576	$ 10,404
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair values	8,576	10,404
U.S. Treasury bills
Marketable Securities [Line Items]
Amortized cost	996	0
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair values	996	0
Money market mutual funds
Marketable Securities [Line Items]
Amortized cost	7,437	10,266
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair values	7,437	10,266
Other short-term interest-bearing securities
Marketable Securities [Line Items]
Amortized cost	143	138
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair values	$ 143	$ 138