Mortgage Servicing Rights ("MSRs") and Related Liabilities - MSRs and Related Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Mortgage Servicing Rights [Line Items]
Mortgage servicing rights at fair value	$ 3,505	$ 3,665
Mortgage servicing rights - fair value and amortized cost	3,511	3,676
Mortgage servicing liabilities - amortized cost	80	71
Excess spread financing - fair value	1,429	1,184
Mortgage servicing rights financing - fair value	43	32
MSR related liabilities - nonrecourse at fair value	1,472	1,216
Mortgage servicing rights
Mortgage Servicing Rights [Line Items]
Mortgage servicing rights at fair value	3,505	3,665
Mortgage servicing right at amortized cost	6	11
Mortgage servicing rights - fair value and amortized cost	3,511	3,676
Mortgage servicing liabilities - amortized cost	$ 80	$ 71

Excess Spread Financing, Fair Value Disclosure

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- Definition

Mortgage Servicing Rights Liability Resulting from Sale or Securitization of Servicer Advances, Rights not Accounted for as a Sale

+ References

No definition available.

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- Definition

Mortgage Servicing Rights [Line Items]

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- Definition

Mortgage Serving Rights Liability, carried at fair value

+ References

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- Definition

Aggregate amount of servicing assets that are subsequently measured at fair value and servicing assets that are subsequently measured using the amortization method.

+ References

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- Definition

Amortized amount of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

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- Definition

Amortized amount of contract to service financial assets under which estimated future revenues from contractually specified servicing fees, late charges, and other ancillary revenue are not expected to adequately compensate the servicer for performing the servicing.

+ References

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