Financial Instruments - Contractual Maturities (Details) $ in Millions	Sep. 30, 2025 USD ($)
Amortized Cost
Due within one year	$ 68,867
Due after one year through five years	8,051
Due after five years through ten years	600
Due after ten years	1,004
Amortized cost	78,522
Estimated Fair Value
Due within one year	68,860
Due after one year through five years	8,098
Due after five years through ten years	599
Due after ten years	985
Estimated fair value	$ 78,542