Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Mortgage Servicing Rights

No definition available.

Name:	coop_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedMortgageServicingRights
Namespace Prefix:	coop_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Servicing Asset at Fair Value, Additions, Servicing Retained From Mortgage Loans Sold

+ References

No definition available.

+ Details

Name:	coop_ServicingAssetatFairValueAdditionsServicingRetainedFromMortgageLoansSold
Namespace Prefix:	coop_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow used to purchase loans that are secured with real estate mortgage and are held with the intention to resell in the near future.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3461-108585

+ Details

Name:	us-gaap_PaymentsToPurchaseMortgageLoansHeldForSale
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The value of new servicing assets, subsequently measured at fair value, acquired or created during the current period through purchases or from transfers of financial assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueAdditions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

Name:	us-gaap_ServicingAssetAtFairValueAmountRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of increase (decrease) in fair value from changes in the inputs, assumptions, or model used to calculate the fair value of the contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(4)(i)
-URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Decrease in servicing assets subsequently measured at fair value resulting from conveyance of servicing rights to unrelated parties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueDisposals
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of increase (decrease) from changes in fair value classified as other for a contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(4)(ii)
-URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueOtherChangesInFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_FairValueByAssetClassAxis=coop_MortgageServicingRightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=coop_PacificUnionFinancialLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=coop_NationstarMortgageHoldingsInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Mortgage Servicing Rights ("MSRs") and Related Liabilities - MSR's at Fair Value (Details) - USD ($) $ in Millions		2 Months Ended	3 Months Ended	7 Months Ended	9 Months Ended
	May 01, 2019	Sep. 30, 2018	Jun. 30, 2019	Jul. 31, 2018	Sep. 30, 2019	Feb. 01, 2019
Servicing Asset at Fair Value, Amount [Roll Forward]
Fair value - beginning of period					$ 3,665
Fair value - end of period					3,339
Mortgage servicing rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Fair value - beginning of period		$ 3,413			3,665
Servicing retained from mortgage loans sold		43			298
Purchases of servicing rights		72	$ 253		732
Sales of servicing assets		(63)			(317)
Changes in valuation inputs or assumptions used in the valuation model		65			(716)
Other changes in fair value		(45)			(323)
Fair value - end of period		3,485		$ 3,413	3,339
Mortgage purchased under subservicing contract	$ 24,000
Pacific Union
Servicing Asset at Fair Value, Amount [Roll Forward]
Mortgage servicing rights						$ 271
Pacific Union \| Mortgage servicing rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Mortgage servicing rights					$ 271
Nationstar Mortgage Holdings Inc. \| Mortgage servicing rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Fair value - beginning of period		$ 3,413		2,937
Servicing retained from mortgage loans sold				162
Purchases of servicing rights				144
Sales of servicing assets				4
Changes in valuation inputs or assumptions used in the valuation model				330
Other changes in fair value				(164)
Fair value - end of period				$ 3,413