Variable Interest Entities - Narrative (Details) - USD ($)	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Variable Interest Entity [Line Items]
Accrued income and other assets	$ 8,803,000,000		$ 8,797,000,000
Accrued expense and other liabilities	4,276,000,000		4,983,000,000
VIE, assets that can only be used to settle obligations	187,409,000,000		187,168,000,000
VIE, liabilities	167,307,000,000		168,992,000,000
Recurring
Variable Interest Entity [Line Items]
Other investments	84,000,000		73,000,000
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
VIE, assets that can only be used to settle obligations	557,000,000		733,000,000
VIE, liabilities	0		1,000,000
Variable Interest Entity, Not Primary Beneficiary | LIHTC
Variable Interest Entity [Line Items]
Accrued income and other assets	2,500,000,000		2,500,000,000
Accrued expense and other liabilities	1,200,000,000		1,400,000,000
VIE, assets that can only be used to settle obligations	11,249,000,000		9,901,000,000
VIE, liabilities	5,057,000,000		4,468,000,000
Variable Interest Entity, Not Primary Beneficiary | NMTC
Variable Interest Entity [Line Items]
Accrued income and other assets	28,000,000		29,000,000
Variable Interest Entity, Not Primary Beneficiary | Other Unconsolidated Variable Interest Entities
Variable Interest Entity [Line Items]
Other investments	118,000,000
Variable Interest Entity, Not Primary Beneficiary | Recurring | Indirect investments
Variable Interest Entity [Line Items]
Other investments	11,000,000		14,000,000
Variable Interest Entity, Not Primary Beneficiary | Investments
Variable Interest Entity [Line Items]
Amortization of investment	200,000,000	$ 171,000,000
Tax credit of investment	195,000,000	166,000,000
Other tax benefits	49,000,000	$ 41,000,000
Variable Interest Entity, Not Primary Beneficiary | Measured at NAV | Recurring | Indirect investments
Variable Interest Entity [Line Items]
Other investments	11,000,000		14,000,000
Variable Interest Entity, Primary Beneficiary | Investments
Variable Interest Entity [Line Items]
VIE, assets that can only be used to settle obligations	0		0
VIE, liabilities	$ 0		$ 0