Compensation - Schedule of Compensation Expense Related to Issuance of Common Stock and Grants of Exchangeability (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Share-Based Payment Arrangement [Abstract]
Issuance of common stock and exchangeability expenses	$ 58,284	$ 52,279

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