Accounting for Transfers and Servicing of Financial Assets and Variable Interest Entities - Additional Information (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Variable Interest Entity [Line Items]
Tax credits related to tax-advantaged investments		$ 152	$ 139
Expense related to tax-advantaged investments		146	$ 138
Investments in VIEs		676,489		$ 678,318
Available-for-sale securities	[1]	86,774		85,992
Liabilities related to VIEs		615,931		619,278
Variable Interest Entity Not Primary Beneficiary | Minimum
Variable Interest Entity [Line Items]
Net investments in unconsolidated VIEs		1		1
Variable Interest Entity Not Primary Beneficiary | Maximum
Variable Interest Entity [Line Items]
Net investments in unconsolidated VIEs		80		79
Variable Interest Entity, Not Primary Beneficiary, Private Investment Funds and Partnerships
Variable Interest Entity [Line Items]
Investments in VIEs		273		264
Maximum exposure to loss		398		382
Variable Interest Entity, Not Primary Beneficiary, Securitization Vehicles | Senior Notes
Variable Interest Entity [Line Items]
Available-for-sale securities		2,700		3,200
Collateral held related to senior notes		3,100		3,600
Variable Interest Entity, Primary Beneficiary, Community Development and Tax-Advantaged Investments
Variable Interest Entity [Line Items]
Investments in VIEs		5,800		6,400
Liabilities related to VIEs		$ 3,500		$ 4,200

[1] Includes only collateral pledged by the Company where counterparties have the right to sell or pledge the collateral.