Fair Value (Fair Value Measurements- Recurring Quantitative Information) (Details) - Fair Value, Measurements, Recurring $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 59,135	$ 147,484
Financial and nonfinancial liabilities, fair value disclosure	(9,378)	(4,518)
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	7,252	5,882
Financial and nonfinancial liabilities, fair value disclosure	(421)	(463)
Recuring Assets, Net of Liabilities - Fair Value	6,831	5,419
Assets, fair value disclosure	7,300	5,900
Level 3 | Loans - Residential real estate | Discounted Cash Flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	76	109
Level 3 | Loans - Residential real estate | Consensus Pricing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 570	$ 622
Level 3 | Loans - Residential real estate | Consensus Pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cumulative default rate	3.60%	3.60%
Level 3 | Loans - Residential real estate | Consensus Pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cumulative default rate	100.00%	100.00%
Level 3 | Loans - Residential real estate | Consensus Pricing | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cumulative default rate	66.20%	74.20%
Level 3 | Loans - Residential real estate | Consensus Pricing with Unobservable Inputs of credit and liquidity discount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		$ 125
Level 3 | Loans - Residential real estate | Consensus Pricing with Unobservable Inputs of credit and liquidity discount | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit and liquidity discount		0.50%
Level 3 | Loans - Residential real estate | Consensus Pricing with Unobservable Inputs of credit and liquidity discount | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit and liquidity discount		100.00%
Level 3 | Loans - Residential real estate | Consensus Pricing with Unobservable Inputs of credit and liquidity discount | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit and liquidity discount		47.30%
Level 3 | Loans - Home equity | Consensus Pricing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 25	$ 28
Level 3 | Loans - Home equity | Consensus Pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cumulative default rate	3.60%	3.60%
Level 3 | Loans - Home equity | Consensus Pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cumulative default rate	100.00%	100.00%
Level 3 | Loans - Home equity | Consensus Pricing | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cumulative default rate	72.50%	75.80%
Level 3 | Loans - Home equity | Consensus Pricing with Unobservable Inputs of credit and liquidity discount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 98
Level 3 | Loans - Home equity | Consensus Pricing with Unobservable Inputs of credit and liquidity discount | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit and liquidity discount	0.40%
Level 3 | Loans - Home equity | Consensus Pricing with Unobservable Inputs of credit and liquidity discount | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit and liquidity discount	100.00%
Level 3 | Loans - Home equity | Consensus Pricing with Unobservable Inputs of credit and liquidity discount | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit and liquidity discount	46.20%
Level 3 | Equity investments | Multiple of Adjusted Earnings
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 1,778	$ 1,680
Level 3 | Equity investments | Multiple of Adjusted Earnings | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Multiple of earnings	0.045	0.050
Level 3 | Equity investments | Multiple of Adjusted Earnings | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Multiple of earnings	0.250	0.144
Level 3 | Equity investments | Multiple of Adjusted Earnings | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Multiple of earnings	9.1	0.088
Level 3 | Insignificant Assets, Net of Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Insignificant assets, fair value disclosure	$ (8)	$ (5)
Residential Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 2,310	$ 1,078
Residential Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Spread over the benchmark curve	2.54%	2.49%
Residential Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Spread over the benchmark curve	16.53%	22.18%
Residential Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Spread over the benchmark curve	7.66%	8.57%
Commercial Mortgages | Level 3 | Loans Held For Sale | Discounted Cash Flow, Spread Over the Benchmark Curve
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 33	$ 49
Commercial Mortgages | Level 3 | Loans Held For Sale | Discounted Cash Flow | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Spread over the benchmark curve	5.85%	5.55%
Commercial Mortgages | Level 3 | Loans Held For Sale | Discounted Cash Flow | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Spread over the benchmark curve	24.65%	159.90%
Commercial Mortgages | Level 3 | Loans Held For Sale | Discounted Cash Flow | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Spread over the benchmark curve	9.59%	99.96%
Commercial Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 1,113	$ 740
Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 819	$ 1,097
Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Spread over the benchmark curve	2.89%	1.63%
Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 124	$ 163
Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Spread over the benchmark curve	2.96%	1.82%
Visa Class B Swap | Level 3 | Financial derivatives | Discounted Cash Flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and nonfinancial liabilities, fair value disclosure	$ (107)	$ (277)
Estimated growth rate of Visa Class A share price	16.00%	16.00%
Visa Class B Swap | Level 3 | Financial derivatives | Discounted Cash Flow | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated conversion factor of Class B shares into Class A shares	160.60%	161.80%
Measurement Input, Constant Default Rate | Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | 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 | Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.130	0.169
Measurement Input, Constant Default Rate | Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.040	0.046
Measurement Input, Constant Default Rate | Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.000	0.014
Measurement Input, Constant Default Rate | Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.073	0.200
Measurement Input, Constant Default Rate | Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.021	0.032
Measurement Input, Loss Severity | Level 3 | Loans - Residential real estate | Discounted Cash Flow | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.060	0.060
Measurement Input, Loss Severity | Level 3 | Loans - Residential real estate | Consensus Pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.000	0.000
Measurement Input, Loss Severity | Level 3 | Loans - Residential real estate | Consensus Pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	1.000	1.000
Measurement Input, Loss Severity | Level 3 | Loans - Residential real estate | Consensus Pricing | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.062	0.069
Measurement Input, Loss Severity | Level 3 | Loans - Home equity | Consensus Pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.000	0.0
Measurement Input, Loss Severity | Level 3 | Loans - Home equity | Consensus Pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	1.000	0.984
Measurement Input, Loss Severity | Level 3 | Loans - Home equity | Consensus Pricing | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.153	0.177
Measurement Input, Loss Severity | Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.150	0.200
Measurement Input, Loss Severity | Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.800	0.964
Measurement Input, Loss Severity | Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.461	0.476
Measurement Input, Loss Severity | Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.200	0.080
Measurement Input, Loss Severity | Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | 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 | Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.490	0.574
Measurement Input, Constant Prepayment Rate | Residential Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | 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 | Residential Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.345	0.410
Measurement Input, Constant Prepayment Rate | Residential Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.067	0.126
Measurement Input, Constant Prepayment Rate | Commercial Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.039	0.050
Measurement Input, Constant Prepayment Rate | Commercial Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.098	0.155
Measurement Input, Constant Prepayment Rate | Commercial Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.043	0.055
Measurement Input, Constant Prepayment Rate | Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | 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 | Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.279	0.307
Measurement Input, Constant Prepayment Rate | Residential mortgage-backed Securities | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.099	0.113
Measurement Input, Constant Prepayment Rate | Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | 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 | Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.400	0.400
Measurement Input, Constant Prepayment Rate | Asset-backed | Level 3 | Securities available for sale | Priced By A Third Party Vendor Using Discounted Cash Flow Pricing Model | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, measurement input	0.075	0.111
Measurement Input, Discount Rate | Level 3 | Loans - Residential real estate | Discounted Cash Flow | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.079	0.035
Measurement Input, Discount Rate | Level 3 | Loans - Residential real estate | Consensus Pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.055	0.048
Measurement Input, Discount Rate | Level 3 | Loans - Residential real estate | Consensus Pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.075	0.068
Measurement Input, Discount Rate | Level 3 | Loans - Residential real estate | Consensus Pricing | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.059	0.052
Measurement Input, Discount Rate | Level 3 | Loans - Home equity | Consensus Pricing | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.055	0.048
Measurement Input, Discount Rate | Level 3 | Loans - Home equity | Consensus Pricing | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.075	0.068
Measurement Input, Discount Rate | Level 3 | Loans - Home equity | Consensus Pricing | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, measurement input	0.065	0.060
Measurement Input, Discount Rate | Commercial Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.078	0.054
Measurement Input, Discount Rate | Commercial Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.101	0.080
Measurement Input, Discount Rate | Commercial Mortgages | Level 3 | Mortgage Servicing Rights | Discounted Cash Flow | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input	0.098	0.078