Fair Value Measurements - Quantitative Information about Recurring Level 3 Fair Value Instruments (Details) - Level 3 - Fair Value $ in Millions	Jun. 30, 2022 USD ($) optionAdjustedSpreadPerLoan $ / loan constantPrepaymentRatePerLoan originationPull-throughRatePerLoan	Dec. 31, 2021 USD ($) $ / loan constantPrepaymentRatePerLoan optionAdjustedSpreadPerLoan originationPull-throughRatePerLoan
Mortgage servicing rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset \| $	$ 622	$ 392
Mortgage servicing rights \| Option adjusted spread \| Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input \| optionAdjustedSpreadPerLoan	0.039	0.039
Mortgage servicing rights \| Option adjusted spread \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input \| optionAdjustedSpreadPerLoan	0.216	0.216
Mortgage servicing rights \| Option adjusted spread \| Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input \| optionAdjustedSpreadPerLoan	0.062	0.071
Mortgage servicing rights \| Constant prepayment rate \| Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input \| constantPrepaymentRatePerLoan	0	0
Mortgage servicing rights \| Constant prepayment rate \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input \| constantPrepaymentRatePerLoan	0.098	0.111
Mortgage servicing rights \| Constant prepayment rate \| Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input \| constantPrepaymentRatePerLoan	0.079	0.092
Mortgage servicing rights \| Weighted average cost to service per loan \| Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input \| $ / loan	67	67
Mortgage servicing rights \| Weighted average cost to service per loan \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input \| $ / loan	90	90
Mortgage servicing rights \| Weighted average cost to service per loan \| Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing asset, measurement input \| $ / loan	79	80
Rate lock commitments (net)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset \| $	$ 25	$ 53
Rate lock commitments (net) \| Origination pull-through rate \| Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, measurement input (as a percent) \| originationPull-throughRatePerLoan	0.762	0.728

Value of input used to measure derivative asset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
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Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Aggregate amount of servicing assets that are subsequently measured at fair value and servicing assets that are subsequently measured using the amortization method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 50
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