The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275

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- Definition

This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118948506&loc=d3e107314-111719

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Mortgage Servicing Rights ("MSRs") and Related Liabilities - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Forward MSRs Sold
Servicing Asset at Amortized Cost [Line Items]
UPB	$ 40,000,000		$ 19,409,000,000
Forward MSRs Sold, Subservicing Retained
Servicing Asset at Amortized Cost [Line Items]
UPB	0		$ 19,276,000,000
Reverse mortgage servicing rights
Servicing Asset at Amortized Cost [Line Items]
UPB	21,590,000,000	$ 22,725,000,000
Mortgage servicing rights
Servicing Asset at Amortized Cost [Line Items]
UPB	290,634,000,000	$ 296,782,000,000
Impairment	$ 0