XML 113 R102.htm IDEA: XBRL DOCUMENT
v3.25.3

Debt - Debt Repurchase Program (Details) - USD ($) | Sep. 30, 2025 | Jun. 16, 2020
--- | --- | ---
Equity, Class of Treasury Stock |  |
Remaining from debt repurchase authorization | $ 50,000,000.0 |
6.125% Senior Notes | Senior Notes |  |
Equity, Class of Treasury Stock |  |
Authorized amount |  | $ 50,000,000.0

X
- Definition Debt Instrument, Debt Repurchase Program Authorized Amount + References No definition available. + Details
Name: | nmrk_DebtInstrumentDebtRepurchaseProgramAuthorizedAmount
Namespace Prefix: | nmrk_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Debt Instrument, Debt Repurchase Program Remaining Authorized Repurchase Amount + References No definition available. + Details
Name: | nmrk_DebtInstrumentDebtRepurchaseProgramRemainingAuthorizedRepurchaseAmount
Namespace Prefix: | nmrk_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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_EquityClassOfTreasuryStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DebtInstrumentAxis=nmrk_SixPointOneTwoFivePercentSeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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