Fair Value (Fair Value Measurements - Recurring Quantitative Information) (Details) $ in Millions	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	$ 62,039	$ 41,785
Fair value of servicing rights	3,711	3,686
Derivative Liability	(3,168)	(3,538)
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	62,039	41,785
Loans, fair value	1,156	1,238
Equity investments	3,132	2,717
Derivative Liability	(5,495)	(5,899)
Fair value assets	77,246	56,862
Fair value liabilities	6,999	6,953
Residential mortgage-backed non-agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	603	696
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments	2,111	1,952
Derivative Liability	(143)	(145)
Insignificant assets, fair value disclosure	45	22
Total recurring assets net of recurring liabilities - fair value	7,094	7,050
Level 3 | Loans - Residential real estate - Uninsured | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, fair value	504	546
Level 3 | Residential real estate | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, fair value	73	75
Level 3 | Loans - Home equity - First-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, fair value	14	18
Level 3 | Loans - Home equity - Second-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, fair value	79	87
Level 3 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	853	956
Loans, fair value	670	726
Equity investments	2,111	1,952
Derivative Liability	(150)	(152)
Fair value assets	7,431	7,448
Fair value liabilities	337	398
Level 3 | Commercial Mortgages
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale, fair value	4	11
Fair value of servicing rights	1,085	1,032
Level 3 | Residential mortgage-backed non-agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	603	696
Level 3 | Asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	93	102
Level 3 | Residential mortgage servicing rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of servicing rights	$ 2,626	$ 2,654
Spread over the benchmark curve | Level 3 | Commercial Mortgages | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.0560	0.0575
Spread over the benchmark curve | Level 3 | Commercial Mortgages | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.1075	0.3610
Spread over the benchmark curve | Level 3 | Commercial Mortgages | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.0970	0.1647
Spread over the benchmark curve | Level 3 | Residential mortgage-backed non-agency securities | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.0216	0.0285
Spread over the benchmark curve | Level 3 | Asset-backed | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.0170	0.0248
Spread over the benchmark curve | Level 3 | Residential mortgage servicing rights | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.0381	0.0337
Spread over the benchmark curve | Level 3 | Residential mortgage servicing rights | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.2202	0.1668
Spread over the benchmark curve | Level 3 | Residential mortgage servicing rights | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.0755	0.0765
Measurement Input, Constant Prepayment Rate | Level 3 | Commercial Mortgages | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.043	0.053
Measurement Input, Constant Prepayment Rate | Level 3 | Commercial Mortgages | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.074	0.097
Measurement Input, Constant Prepayment Rate | Level 3 | Commercial Mortgages | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.044	0.055
Measurement Input, Constant Prepayment Rate | Level 3 | Residential mortgage-backed non-agency securities | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.010	0.010
Measurement Input, Constant Prepayment Rate | Level 3 | Residential mortgage-backed non-agency securities | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.279	0.279
Measurement Input, Constant Prepayment Rate | Level 3 | Residential mortgage-backed non-agency securities | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.042	0.037
Measurement Input, Constant Prepayment Rate | Level 3 | Asset-backed | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.010	0.010
Measurement Input, Constant Prepayment Rate | Level 3 | Asset-backed | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.080	0.280
Measurement Input, Constant Prepayment Rate | Level 3 | Asset-backed | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.038	0.051
Measurement Input, Constant Prepayment Rate | Level 3 | Residential mortgage servicing rights | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.000	0.000
Measurement Input, Constant Prepayment Rate | Level 3 | Residential mortgage servicing rights | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.403	0.336
Measurement Input, Constant Prepayment Rate | Level 3 | Residential mortgage servicing rights | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.064	0.064
Measurement Input, Constant Default Rate | Level 3 | Residential mortgage-backed non-agency securities | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.000	0.000
Measurement Input, Constant Default Rate | Level 3 | Residential mortgage-backed non-agency securities | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.120	0.120
Measurement Input, Constant Default Rate | Level 3 | Residential mortgage-backed non-agency securities | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.019	0.027
Measurement Input, Constant Default Rate | Level 3 | Asset-backed | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.000	0.000
Measurement Input, Constant Default Rate | Level 3 | Asset-backed | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.071	0.043
Measurement Input, Constant Default Rate | Level 3 | Asset-backed | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.015	0.017
Cumulative default rate | Level 3 | Minimum | Loans - Residential real estate - Uninsured | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.036	0.036
Cumulative default rate | Level 3 | Minimum | Loans - Home equity - First-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.036	0.036
Cumulative default rate | Level 3 | Maximum | Loans - Residential real estate - Uninsured | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	1.000	1.000
Cumulative default rate | Level 3 | Maximum | Loans - Home equity - First-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	1.000	1.000
Cumulative default rate | Level 3 | Weighted Average | Loans - Residential real estate - Uninsured | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.525	0.591
Cumulative default rate | Level 3 | Weighted Average | Loans - Home equity - First-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.516	0.609
Measurement Input, Loss Severity | Level 3 | Minimum | Loans - Residential real estate - Uninsured | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.000	0.000
Measurement Input, Loss Severity | Level 3 | Minimum | Loans - Home equity - First-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.000	0.0
Measurement Input, Loss Severity | Level 3 | Maximum | Loans - Residential real estate - Uninsured | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	1.000	1.000
Measurement Input, Loss Severity | Level 3 | Maximum | Loans - Home equity - First-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	1.000	1.000
Measurement Input, Loss Severity | Level 3 | Weighted Average | Loans - Residential real estate - Uninsured | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.050	0.054
Measurement Input, Loss Severity | Level 3 | Weighted Average | Residential real estate | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.060	0.060
Measurement Input, Loss Severity | Level 3 | Weighted Average | Loans - Home equity - First-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.123	0.144
Measurement Input, Loss Severity | Level 3 | Residential mortgage-backed non-agency securities | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.150	0.100
Measurement Input, Loss Severity | Level 3 | Residential mortgage-backed non-agency securities | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.690	0.690
Measurement Input, Loss Severity | Level 3 | Residential mortgage-backed non-agency securities | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.424	0.412
Measurement Input, Loss Severity | Level 3 | Asset-backed | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.350	0.200
Measurement Input, Loss Severity | Level 3 | Asset-backed | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	1.000	1.000
Measurement Input, Loss Severity | Level 3 | Asset-backed | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.453	0.495
Measurement Input, Discount Rate | Level 3 | Minimum | Loans - Residential real estate - Uninsured | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.055	0.055
Measurement Input, Discount Rate | Level 3 | Minimum | Loans - Home equity - First-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.055	0.055
Measurement Input, Discount Rate | Level 3 | Maximum | Loans - Residential real estate - Uninsured | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.075	0.075
Measurement Input, Discount Rate | Level 3 | Maximum | Loans - Home equity - First-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.075	0.075
Measurement Input, Discount Rate | Level 3 | Weighted Average | Loans - Residential real estate - Uninsured | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.057	0.058
Measurement Input, Discount Rate | Level 3 | Weighted Average | Residential real estate | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.072	0.078
Measurement Input, Discount Rate | Level 3 | Weighted Average | Loans - Home equity - First-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.061	0.062
Measurement Input, Discount Rate | Level 3 | Commercial Mortgages | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.096	0.076
Measurement Input, Discount Rate | Level 3 | Commercial Mortgages | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.115	0.100
Measurement Input, Discount Rate | Level 3 | Commercial Mortgages | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.112	0.096
Credit and liquidity discount | Level 3 | Minimum | Loans - Home equity - Second-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.003	0.003
Credit and liquidity discount | Level 3 | Maximum | Loans - Home equity - Second-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	1.000	1.000
Credit and liquidity discount | Level 3 | Weighted Average | Loans - Home equity - Second-lien | Total consumer lending
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financing receivable, measurement input	0.412	0.438
Multiple of earnings | Level 3 | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, measurement input	0.055	0.045
Multiple of earnings | Level 3 | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, measurement input	0.267	0.267
Multiple of earnings | Level 3 | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, measurement input	0.105	0.101
Estimated Conversion Factor | Level 3 | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	1.54	1.59
Estimated Annual Growth Rate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	0.160	0.160