Financial Instruments - Fair Values on Recurring Basis (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Equity Securities, FV-NI, Gain (Loss)
Equity securities, unrealized gain (loss)	$ (205)	$ (2,100)
Recurring
Schedule of Investments [Line Items]
Cash	15,794		$ 17,055
Debt Securities, Available-for-sale
Gross unrealized gains	16
Gross unrealized losses	(83)
Cash, Cash Equivalents, and Marketable Securities
Cash, cash equivalents and marketable securities	98,251		104,735
Cash, cash equivalents and marketable securities, amortized cost	95,317
Less: Restricted cash, cash equivalents, and marketable securities	(3,686)		(3,533)
Total cash, cash equivalents, and marketable securities	94,565		101,202
Recurring | Level 1 securities
Schedule of Investments [Line Items]
Equity securities	3,001		3,318
Recurring | Level 1 securities | Money market funds
Schedule of Investments [Line Items]
Money market funds	18,357		28,282
Recurring | Level 1 securities | Money market funds | Money market funds
Schedule of Investments [Line Items]
Money market funds	18,357
Recurring | Level 2 securities | Foreign government and agency securities
Debt Securities, Available-for-sale
Fixed income securities, amortized cost	180
Gross unrealized gains	0
Gross unrealized losses	0
Fixed income securities	180		177
Recurring | Level 2 securities | U.S. government and agency securities
Debt Securities, Available-for-sale
Fixed income securities, amortized cost	4,709
Gross unrealized gains	5
Gross unrealized losses	(40)
Fixed income securities	4,674		3,401
Recurring | Level 2 securities | Corporate debt securities
Debt Securities, Available-for-sale
Fixed income securities, amortized cost	54,744
Gross unrealized gains	9
Gross unrealized losses	(28)
Fixed income securities	54,725		50,912
Recurring | Level 2 securities | Asset-backed securities
Debt Securities, Available-for-sale
Fixed income securities, amortized cost	1,471
Gross unrealized gains	2
Gross unrealized losses	(15)
Fixed income securities	1,458		1,523
Recurring | Level 2 securities | Other debt securities
Debt Securities, Available-for-sale
Fixed income securities, amortized cost	62
Gross unrealized gains	0
Gross unrealized losses	0
Fixed income securities	$ 62		$ 67