Accounting for Transfers and Servicing of Financial Assets and Variable Interest Entities - Additional Information (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Variable Interest Entity [Line Items]
Tax credits related to tax-advantaged investments		$ 184	$ 141	$ 548	$ 424
Expense related to tax-advantaged investments		151	$ 135	452	$ 418
Investments in VIEs		695,357		695,357		$ 678,318
Available-for-sale securities	[1]	89,065		89,065		85,992
Liabilities related to VIEs		631,559		631,559		619,278
Variable Interest Entity Not Primary Beneficiary | Minimum
Variable Interest Entity [Line Items]
Net investments in unconsolidated VIEs		1		1		1
Variable Interest Entity Not Primary Beneficiary | Maximum
Variable Interest Entity [Line Items]
Net investments in unconsolidated VIEs		100		100		79
Variable Interest Entity, Not Primary Beneficiary, Private Investment Funds and Partnerships
Variable Interest Entity [Line Items]
Investments in VIEs		309		309		264
Maximum exposure to loss		423		423		382
Variable Interest Entity, Not Primary Beneficiary, Securitization Vehicles | Senior Notes
Variable Interest Entity [Line Items]
Available-for-sale securities		2,000		2,000		3,200
Collateral held related to senior notes		2,300		2,300		3,600
Variable Interest Entity, Primary Beneficiary, Community Development and Tax-Advantaged Investments
Variable Interest Entity [Line Items]
Investments in VIEs		5,900		5,900		6,400
Liabilities related to VIEs		$ 3,600		$ 3,600		$ 4,200

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