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
	Mar. 31, 2026	Mar. 31, 2025
Net  derivative liabilities
Beginning balance	$ (25)	$ (15)
Total net gains (losses) included in net income	0	(5)
Sales		0
Settlements	7	2
Net transfers into (out of) Level 3	0	0
Ending balance	(18)	(18)
Net unrealized gains (losses) included in net income	0	(5)
SBA interest-only strips
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	45	23
Total net gains (losses) included in net income	(2)	(2)
Sales		(3)
Settlements	0	0
Net transfers into (out of) Level 3	(8)	4
Ending balance	35	22
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	14	16
Total net gains (losses) included in net income	0	0
Sales		(4)
Settlements	0	0
Net transfers into (out of) Level 3	0	1
Ending balance	14	13
Net unrealized gains (losses) included in net income	$ 0	$ 0