Fair Value of Assets and Liabilities - Schedule of Changes in Level 3 Assets and Liabilities Measured at Fair Value (Details) - Level 3 - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Net  derivative liabilities
Beginning balance	$ (15)	$ (23)
Total net gains (losses) included in net income	(5)	0
Purchases		0
Sales	0	0
Settlements	2	3
Net transfers into (out of) Level 3	0	0
Ending balance	(18)	(20)
Net unrealized gains (losses) included in net income	(5)	0
SBA interest-only strips
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	23	13
Total net gains (losses) included in net income	(2)	(1)
Purchases		0
Sales	(3)	(2)
Settlements	0	0
Net transfers into (out of) Level 3	4	9
Ending balance	22	19
Net unrealized gains (losses) included in net income	(1)	(1)
Loans held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	16	26
Total net gains (losses) included in net income	0	0
Purchases		1
Sales	(4)	(13)
Settlements	0	0
Net transfers into (out of) Level 3	1	0
Ending balance	13	14
Net unrealized gains (losses) included in net income	$ 0	$ 0