Exchangeable Partnership Units

No definition available.

Name:	nmrk_ExchangeablePartnershipUnits
Namespace Prefix:	nmrk_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Limited partnership units exchange ratio.

+ References

No definition available.

+ Details

Name:	nmrk_LimitedPartnershipUnitsExchangeRatio
Namespace Prefix:	nmrk_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Share-based compensation arrangement by share-based payment award, number of shares registered.

+ References

No definition available.

+ Details

Name:	nmrk_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesRegistered
Namespace Prefix:	nmrk_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

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

- Definition

The number of limited partner units outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187171-122770

+ Details

Name:	us-gaap_LimitedPartnersCapitalAccountUnitsOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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

- Definition

Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares issued under share-based payment arrangement.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of options vested.

+ References

No definition available.

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_TitleOfIndividualAxis=nmrk_ExecutivesAndNonExecutivesEmployeesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CapitalUnitsByClassAxis=nmrk_NonDistributionEarningUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=nmrk_NewmarkHoldingsLimitedPartnershipMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=srt_ParentCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=nmrk_LimitedPartnershipUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=nmrk_BGCHoldingsLimitedPartnershipMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=nmrk_LimitedPartnershipUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=nmrk_LongTermEquityIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Compensation - Narrative (Details) $ in Millions	12 Months Ended
Compensation - Narrative (Details) $ in Millions	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 shares	Dec. 31, 2020 shares	Dec. 13, 2017 shares
Share-based Compensation Arrangement by Share-based Payment Award
Shares available for future awards (in shares)	320,300,000
Limited partnership units exchange ratio	0.4545
Number of shares vested and converted (in shares)	11,800,000
Unrecognized compensation expense related to unvested RSUs \| $	$ 100.1
Executives And Non Executives Employees
Share-based Compensation Arrangement by Share-based Payment Award
Limited partners capital account units held by BGC (in shares)	79,700,000
Non Distribution Earning Units
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting period	4 years
Unit granted during period (in shares)	4,400,000	3,700,000
Newmark Holdings, L.P.
Share-based Compensation Arrangement by Share-based Payment Award
Limited partnership units exchange ratio	0.4545
NEWMARK Group Inc Parent
Share-based Compensation Arrangement by Share-based Payment Award
Limited partners capital account units held by BGC (in shares)	14,277,213	11,691,406
Limited partnership units outstanding (in shares)	30,687,954	18,419,613	66,626,185
NEWMARK Group Inc Parent \| Limited Partnership Units
Share-based Compensation Arrangement by Share-based Payment Award
Limited partnership units outstanding (in shares)	3,900,000	4,200,000
Exchangeable partnership units (in shares)	1,500,000	1,300,000
BGC Holdings, L.P.
Share-based Compensation Arrangement by Share-based Payment Award
Limited partnership units outstanding (in shares)	5,459,388	8,663,930	54,422,002
BGC Holdings, L.P. \| Limited Partnership Units
Share-based Compensation Arrangement by Share-based Payment Award
Limited partnership units outstanding (in shares)	4,800,000	6,800,000
Exchangeable partnership units (in shares)	2,500,000	3,100,000
Maximum \| NEWMARK Group Inc Parent \| Limited Partnership Units
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting period	7 years
Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award
Limited partnership units exchange ratio				1
Class A Common Stock \| NEWMARK Group Inc Parent
Share-based Compensation Arrangement by Share-based Payment Award
Limited partnership units exchange ratio	0.9303
Newmark Equity Plan \| Class A Common Stock \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Shares authorized to be delivered pursuant to awards granted (in shares)				400,000,000
Shares registered to be delivered pursuant to awards granted (in shares)				115,000,000