Compensation - Compensation Expense Related to Limited Partnership Units that were Not Redeemed (Details) - NEWMARK Group Inc - Limited Partnership Units - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award
Post-termination payout	$ 3,282	$ 4,861
Stated vesting schedule	4,065	2,710
Limited partnership units amortization	$ 7,347	$ 7,571