Name:	nsm_ContractuallySpecifiedServicingFeesLateFeesandAncillaryFeesEarnedinExchangeforServicingFinancialAssetsRevenueRecognized
Namespace Prefix:	nsm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Excess spread financing (at fair value)

No definition available.

Name:	nsm_ExcessSpreadFinancingAtFairValue
Namespace Prefix:	nsm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Forward Mortgage Loans Subserviced, Unpaid Principal Balance Boarded

No definition available.

Name:	nsm_ForwardMortgageLoansSubservicedUnpaidPrincipalBalanceBoarded
Namespace Prefix:	nsm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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

No definition available.

Name:	nsm_MortgageServicingRightsLiabilityResultingfromSaleofServicerAdvancesRightsnotAccountedforasaSale
Namespace Prefix:	nsm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Payments for Servicing Fees

No definition available.

Name:	nsm_PaymentsforServicingFees
Namespace Prefix:	nsm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Income from mortgage banking activities (fees and commissions) and servicing real estate mortgages, credit cards, and other financial assets held by others net of any related impairment of capitalized service costs. Also includes any premiums received in lieu of regular servicing fees on such loans only as earned over the life of the loans.

No definition available.

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

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.

No definition available.

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

Name:	srt_CounterpartyNameAxis=nsm_NewResidentialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementScenarioAxis=us-gaap_PredecessorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=nsm_SubsidiaryofNewResidentialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionAxis=nsm_LoanSubservicingAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: