Derivative Instruments and Hedging Activities - Hedged Items in Fair Value Hedging Relationship (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Hedged Items In Fair Value Hedging Relationship [Line Items]
Total Assets	$ 15	$ (16)
Discontinued Hedging Relationships, Assets	3,500	3,400
Designated hedged items	2,200	2,100
Investment securities available for sale
Hedged Items In Fair Value Hedging Relationship [Line Items]
Carrying Amount Assets	8,793	8,312
Total Assets	42	(38)
Discontinued Hedging Relationships, Assets	60	78
Interest-bearing deposits
Hedged Items In Fair Value Hedging Relationship [Line Items]
Carrying Amount Liabilities	(10,317)	(10,331)
Total Liabilities	85	160
Discontinued Hedging Relationships, Liabilities	0	0
Securitized debt obligations
Hedged Items In Fair Value Hedging Relationship [Line Items]
Carrying Amount Liabilities	(8,838)	(11,011)
Total Liabilities	202	276
Discontinued Hedging Relationships, Liabilities	0	0
Senior and subordinated notes
Hedged Items In Fair Value Hedging Relationship [Line Items]
Carrying Amount Liabilities	(29,459)	(30,696)
Total Liabilities	628	1,069
Discontinued Hedging Relationships, Liabilities	$ (194)	$ (225)