Line Of Credit Facility, Decrease, Cancelled

No definition available.

Name:	nmrk_LineOfCreditFacilityDecreaseCancelled
Namespace Prefix:	nmrk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum amount of borrowing capacity under a line of credit that is available as of the balance sheet date for a specific purpose other than for financing goods acquired for inventory or imminent delivery to a customer.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_SecuritiesFinancingTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying value as of the balance sheet date of the outstanding short-term borrowings under a revolving line of credit used by mortgage bankers to finance the origination or purchase of loans.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

+ Details

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

- Details

Name:	us-gaap_CreditFacilityAxis=nmrk_CommittedLinesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=nmrk_UncommittedLinesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_CreditFacilityAxis=nmrk_SublimitLinesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

Warehouse Facilities Collateralized by U.S. Government Sponsored Enterprises (Details) - USD ($)	9 Months Ended
	Sep. 30, 2024	May 07, 2024	Dec. 31, 2023
Securities Financing Transaction
Outstanding draws	$ 985,801,000		$ 498,631,000
Committed Lines
Securities Financing Transaction
Lines available	1,450,000,000
Uncommitted Lines
Securities Financing Transaction
Lines available	1,500,000,000
Warehouse facility due May 6, 2025
Securities Financing Transaction
Outstanding draws	$ 151,072,000		0
Basis spread on variable rate	1.30%
Warehouse facility due May 6, 2025 \| Committed Lines
Securities Financing Transaction
Lines available	$ 450,000,000
Basis spread on variable rate	1.80%
Warehouse facility due May 6, 2025 \| Uncommitted Lines
Securities Financing Transaction
Lines available	$ 300,000,000
Warehouse facility due May 6, 2025 \| Sublimit Lines
Securities Financing Transaction
Lines available	125,000,000.0
Outstanding draws	0		0
Line of credit facility, decrease, cancelled		$ 125,000,000
Warehouse facility due September 25, 2024
Securities Financing Transaction
Outstanding draws	$ 287,130,000		94,873,000
Basis spread on variable rate	1.30%
Warehouse facility due September 25, 2024 \| Committed Lines
Securities Financing Transaction
Lines available	$ 200,000,000
Warehouse facility due September 25, 2024 \| Uncommitted Lines
Securities Financing Transaction
Lines available	200,000,000
Warehouse Facility Due October 5, 2024
Securities Financing Transaction
Outstanding draws	$ 528,357,000		403,758,000
Basis spread on variable rate	1.30%
Warehouse Facility Due October 5, 2024 \| Committed Lines
Securities Financing Transaction
Lines available	$ 800,000,000
Warehouse Facility Due October 5, 2024 \| Uncommitted Lines
Securities Financing Transaction
Lines available	600,000,000
Fannie Mae repurchase agreement, open maturity
Securities Financing Transaction
Outstanding draws	$ 19,242,000		$ 0
Basis spread on variable rate	1.15%
Fannie Mae repurchase agreement, open maturity \| Uncommitted Lines
Securities Financing Transaction
Lines available	$ 400,000,000