Disposal Group, Not Discontinued Operation, Transaction Cost

No definition available.

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

- Definition

Amount of currency on hand, demand deposits with banks or financial institutions, and other kinds of accounts that have the general characteristics of demand deposits, held by a disposal group.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

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

- Definition

Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123351718&loc=d3e2443-110228

Reference 2: 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=123570139&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230

+ Details

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

- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types: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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=nsm_TitleBusinessMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	dei_LegalEntityAxis=nsm_MrCooperGroupIncMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	srt_OwnershipAxis=nsm_BlendLabsIncMember
Namespace Prefix:
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Nature of Business and Basis of Presentation - Additional Information (Details) - Disposal Group, Disposed of by Sale, Not Discontinued Operations - Title Business - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Mar. 12, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Purchase price			$ 500
Cash received from disposal			$ 450
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 487
Disposal Group, Not Discontinued Operation, Transaction Cost	$ 2	$ 5
Mr. Cooper Group Inc. \| Blend Labs, Inc.
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Ownership interest percentage			9.90%