Investment Securities - Proceeds and Gross Realized Gains And Losses from Sales of Securities Available for Sale (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023		Sep. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Proceeds	$ 3,485	$ 10,549	$ 6,385	[1]	$ 24,019	[1]
Gross realized gains	1	16	1		156
Gross realized losses	$ 25	$ 32	$ 45		$ 155

[1] Certain prior period amounts have been reclassified to conform to the current year presentation. See Note 1 for additional information.