Debt Instrument, Call Date, Weighted Average Term

No definition available.

Name:	coop_DebtInstrumentCallDateWeightedAverageTerm
Namespace Prefix:	coop_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Principal Amount Outstanding

+ References

No definition available.

+ Details

Name:	coop_DebtInstrumentPrincipalAmountOutstanding
Namespace Prefix:	coop_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum percentage redeemable of aggregate principal on unsecured debt with the net proceeds of certain equity offerings at a fixed redemption prices, plus accrued and unpaid interest and additional interest, if any, to the redemption dates, subject to compliance with certain conditions.

+ References

No definition available.

+ Details

Name:	coop_MaximumPercentageRedeemableofAggregatePrincipalonUnsecuredDebt
Namespace Prefix:	coop_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum Tangible Net Worth Required for Compliance

+ References

No definition available.

+ Details

Name:	coop_MinimumTangibleNetWorthRequiredForCompliance
Namespace Prefix:	coop_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Payment for Repurchase of Unsecured Debt

+ References

No definition available.

+ Details

Name:	coop_PaymentforRepurchaseofUnsecuredDebt
Namespace Prefix:	coop_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

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.

+ Details

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

- Definition

Amount of gain (loss) from the difference between the repurchase price of a debt instrument initially issued by the entity and the net carrying amount of the debt at the time of its repurchase.

+ References

No definition available.

+ Details

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

- Definition

Amount of debt for which creditor does not have general recourse to the debtor but rather has recourse only to the property used for collateral in the transaction or other specific property.

+ References

No definition available.

+ Details

Name:	us-gaap_NonRecourseDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This is the principal amount outstanding for securitized loans only (across all types of loans).

+ 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

+ Details

Name:	us-gaap_PrincipalAmountOutstandingOnLoansSecuritized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=coop_NewNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=coop_NonrecourseDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=coop_HECMSecuritizationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Indebtedness - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
Indebtedness - Narrative (Details) - USD ($)	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Nov. 30, 2009
Debt Instrument [Line Items]
Repurchase of unsecured senior notes			$ 0	$ 62,000,000
Principal amount outstanding on securitized financing						$ 222,000,000
Non-recourse debt	$ 5,985,000,000		5,985,000,000		$ 6,795,000,000
Minimum tangible net worth	682,000,000		682,000,000
Securities Pledged as Collateral
Debt Instrument [Line Items]
Principal amount outstanding on securitized financing	151,000,000		$ 151,000,000		160,000,000
New Notes
Debt Instrument [Line Items]
Maximum percentage redeemable on unsecured debt			40.00%
Unsecured Senior Notes
Debt Instrument [Line Items]
Maximum percentage redeemable on unsecured debt			35.00%
Nonrecourse debt–legacy assets
Debt Instrument [Line Items]
Carrying value on loans outstanding	22,000,000		$ 22,000,000		29,000,000
Non-recourse debt	22,000,000		22,000,000		$ 29,000,000
Unsecured Senior Notes
Debt Instrument [Line Items]
Repurchase of unsecured senior notes	$ 0	$ 44,000,000	$ 0	60,000,000
Loss on repurchase of debt		$ 1,000,000		$ 2,000,000
Secured Debt \| Nonrecourse debt–legacy assets
Debt Instrument [Line Items]
Interest rate	7.50%		7.50%
Minimum \| Nonrecourse debt–legacy assets
Debt Instrument [Line Items]
Interest rate	2.718%		2.718%
Minimum \| Secured Debt \| HECM Securitizations
Debt Instrument [Line Items]
Interest rate	2.70%		2.70%
Weighted average useful life			1 year
Maximum \| Nonrecourse debt–legacy assets
Debt Instrument [Line Items]
Interest rate	5.97%		5.97%
Maximum \| Secured Debt \| HECM Securitizations
Debt Instrument [Line Items]
Interest rate	6.00%		6.00%
Weighted average useful life			4 years