Financial Instruments - Contractual Maturities (Details) $ in Millions	Mar. 31, 2024 USD ($)
Amortized Cost
Due within one year	$ 66,539
Due after one year through five years	3,810
Due after five years through ten years	404
Due after ten years	875
Amortized cost	71,628
Estimated Fair Value
Due within one year	66,481
Due after one year through five years	3,652
Due after five years through ten years	389
Due after ten years	824
Estimated fair value	$ 71,346