Financial Instruments - Fair Values on Recurring Basis (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Equity Securities, FV-NI, Gain (Loss)
Equity securities, unrealized gain (loss)	$ 1,000	$ (13,600)	$ 11,600
Recurring
Schedule of Investments [Line Items]
Cash	11,706	10,666
Cost or Amortized Cost
Cash, cash equivalents and short-term investments	82,971	67,484
Gross Unrealized Gains
Cash equivalents and marketable securities	1	0
Gross Unrealized Losses
Cash equivalents and marketable securities	(347)	(802)
Total Estimated Fair Value
Cash, cash equivalents and short-term investments	87,283	70,391
Less: Restricted cash, cash equivalents, and marketable securities	(503)	(365)
Total cash, cash equivalents, and marketable securities	86,780	70,026
Recurring | Level 1 securities
Total Estimated Fair Value
Equity securities	4,658	3,709
Recurring | Level 1 securities | Money market funds
Schedule of Investments [Line Items]
Money market funds	39,160	27,899
Recurring | Level 1 securities | Money market funds | Money market funds
Schedule of Investments [Line Items]
Money market funds	39,160
Recurring | Level 2 securities | Foreign government and agency securities
Cost or Amortized Cost
Cash equivalents and marketable securities	505	537
Gross Unrealized Gains
Cash equivalents and marketable securities	0	0
Gross Unrealized Losses
Cash equivalents and marketable securities	0	(2)
Total Estimated Fair Value
Cash equivalents and marketable securities	505	535
Recurring | Level 2 securities | U.S. government and agency securities
Cost or Amortized Cost
Cash equivalents and marketable securities	1,789	2,301
Gross Unrealized Gains
Cash equivalents and marketable securities	1	0
Gross Unrealized Losses
Cash equivalents and marketable securities	(91)	(155)
Total Estimated Fair Value
Cash equivalents and marketable securities	1,699	2,146
Recurring | Level 2 securities | Corporate debt securities
Cost or Amortized Cost
Cash equivalents and marketable securities	27,996	23,111
Gross Unrealized Gains
Cash equivalents and marketable securities	0	0
Gross Unrealized Losses
Cash equivalents and marketable securities	(191)	(484)
Total Estimated Fair Value
Cash equivalents and marketable securities	27,805	22,627
Recurring | Level 2 securities | Asset-backed securities
Cost or Amortized Cost
Cash equivalents and marketable securities	1,707	2,721
Gross Unrealized Gains
Cash equivalents and marketable securities	0	0
Gross Unrealized Losses
Cash equivalents and marketable securities	(61)	(149)
Total Estimated Fair Value
Cash equivalents and marketable securities	1,646	2,572
Recurring | Level 2 securities | Other debt securities
Cost or Amortized Cost
Cash equivalents and marketable securities	108	249
Gross Unrealized Gains
Cash equivalents and marketable securities	0	0
Gross Unrealized Losses
Cash equivalents and marketable securities	(4)	(12)
Total Estimated Fair Value
Cash equivalents and marketable securities	$ 104	$ 237