Amortized Cost and Fair Value of Available for Sale Securities by Expected Maturity (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Amortized Cost [Abstract]
Due in one year or less	$ 1,783	$ 570
Due after one year through five years	9,239	8,355
Due after five years through ten years	542	985
Due after ten years	16	2
Total amortized cost	11,580	9,912
Fair Value [Abstract]
Due in one year or less	1,771	566
Due after one year through five years	8,466	7,661
Due after five years through ten years	495	855
Due after ten years	15	2
Total fair value	$ 10,747	$ 9,084