Fair Value of Assets and Liabilities - Schedule of Changes in Level 3 Assets and Liabilities Measured at Fair Value (Details) - Level 3 - Recurring - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Net  derivative liabilities
Beginning balance	$ (13)	$ (18)	$ (15)	$ (23)
Total net gains (losses) included in net income	(10)	(15)	(15)	(15)
Purchases	0		0	0
Sales	0	0	0	0
Settlements	1	1	8	6
Net transfers into (out of) Level 3	0	0	0	0
Ending balance	(22)	(32)	(22)	(32)
Net unrealized gains (losses) included in net income	(10)	(15)	(15)	(15)
SBA interest-only strips
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	27	16	23	13
Total net gains (losses) included in net income	(1)	(1)	(5)	(3)
Purchases	0		0	0
Sales	(8)	(5)	(11)	(15)
Settlements	0	0	0	0
Net transfers into (out of) Level 3	8	7	19	22
Ending balance	26	17	26	17
Net unrealized gains (losses) included in net income	(1)	0	(2)	(1)
Loans held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	12	15	16	26
Total net gains (losses) included in net income	1	1	1	1
Purchases	1		1	2
Sales	0	0	(5)	(13)
Settlements	(1)	(1)	(1)	(2)
Net transfers into (out of) Level 3	0	1	1	2
Ending balance	13	16	13	16
Net unrealized gains (losses) included in net income	$ 1	$ 1	$ 1	$ 1