Compensation - Compensation Expense Related to Issuance of Common Stock and Grants of Exchangeability (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Issuance of common stock and exchangeability expenses	$ 30,059	$ 15,056	$ 78,017	$ 42,762

Common Stock, Exchangeability Granted, Issued, Expense

No definition available.

Name:	nmrk_CommonStockExchangeabilityGrantedIssuedExpense
Namespace Prefix:	nmrk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration