Investment Securities - Amortized Cost and Fair Value of Available-for-Sale Debt and Held-to-Maturity Securities (Details) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022
Available-for-Sale Debt and Other, Amortized Cost
Due in 1 year or less		$ 756
Due after 1 year through 5 years		18,493
Due after 5 years through 10 years		26,194
Due after 10 years		9,624
Other securities		722
Amortized Cost		55,789	$ 57,530
Available-for-Sale Debt and Other, Fair Value
Due in 1 year or less		746
Due after 1 year through 5 years		17,429
Due after 5 years through 10 years		23,165
Due after 10 years		8,357
Other securities		722
Fair Value	[1]	50,419	51,503
Held-to-Maturity, Amortized Cost
Due in 1 year or less		0
Due after 1 year through 5 years		0
Due after 5 years through 10 years		0
Due after 10 years		2
Other securities		0
Amortized Cost	[2]	2	5
Held-to-Maturity, Fair Value
Due in 1 year or less		0
Due after 1 year through 5 years		0
Due after 5 years through 10 years		0
Due after 10 years		2
Other securities		0
Fair Value		$ 2	$ 5

[1] Amortized cost of $55,789 and $57,530 at December 31, 2023 and 2022, respectively.

[2] Fair value of $2 and $5 at December 31, 2023 and 2022, respectively.