Fair Value of Assets and Liabilities - Schedule of Changes in Level 3 Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other expense	Other expense	Other expense
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other expense	Other expense
Level 3
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	$ (23)	$ (27)	$ (23)
Total net gains (losses) included in net income	(15)	(15)	(23)
Purchases	0	0	0
Sales	0	0	0
Settlements	23	19	19
Repayments			0
Net transfers into (out of) Level 3	0	0	0
Ending balance	(15)	(23)	(27)
Net unrealized gains (losses) included in net income	(15)	(15)	(23)
SBA interest-only strips | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	13	25	38
Total net gains (losses) included in net income	(5)	(12)	(7)
Purchases	0	0	0
Sales	(17)	(54)	(76)
Settlements	0	0	0
Repayments			0
Net transfers into (out of) Level 3	32	54	70
Ending balance	23	13	25
Net unrealized gains (losses) included in net income	(2)	(1)	(2)
Loans held for sale | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	26	22	28
Total net gains (losses) included in net income	1	4	0
Purchases	2	3	2
Sales	(13)	(3)	(12)
Settlements	(2)	(2)	(2)
Repayments			(1)
Net transfers into (out of) Level 3	2	2	7
Ending balance	16	26	22
Net unrealized gains (losses) included in net income	$ 1	$ 4	$ 0