Financial Instruments - Carrying Values for Marketable and Non-Marketable Equity Securities (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Marketable Equity Securities
Total initial cost	$ 4,423	$ 4,767
Cumulative net gain (loss)	1,552	312
Carrying value	5,975	5,079
Non-Marketable Equity Securities
Total initial cost	26,152	21,240
Cumulative net gain (loss)	23,682	14,291
Carrying value	49,834	35,531
Total
Total initial cost	30,575	26,007
Cumulative net gain (loss)	25,234	14,603
Carrying value	55,809	40,610
Cumulative net gain of non-marketable securities	32,800	22,700
Unrealized loss of non-marketable securities	$ 9,100	$ 8,400