Cash, Cash Equivalents, and Marketable Securities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash, Cash Equivalents, and Short-term Investments	$ 8,485	$ 8,744
Total cash and cash equivalents	8,848	10,658
Restricted Cash	102	137
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	8,950	10,795	$ 9,448	$ 10,520
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents	363	1,914
Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Marketable securities	714	789
US Government [Member] | Fair Value, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents	86	912
Marketable securities	219	207
US Government Agencies [Member] | Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents	0	625
Marketable securities	0	49
Debt Security, Government, Non-US [Member] | Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents	277	276
Marketable securities	83	109
Corporate debt [Member] | Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents	0	101
Marketable securities	261	268
Other Debt Obligations [Member] | Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Marketable securities	$ 151	$ 156