Financial Instruments - Contractual Maturities (Details) $ in Millions	Sep. 30, 2023 USD ($)
Amortized Cost
Due within one year	$ 43,198
Due after one year through five years	5,623
Due after five years through ten years	453
Due after ten years	1,103
Amortized cost	50,377
Estimated Fair Value
Due within one year	43,132
Due after one year through five years	5,284
Due after five years through ten years	429
Due after ten years	1,026
Estimated fair value	$ 49,871