Compensation - Compensation Expense Related to Limited Partnership Units that were Not Redeemed (Details) - Newmark Holdings Units - Limited Partnership Units - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award
Post-termination payout	$ 3,026	$ 1,532	$ 9,412	$ 9,762
Stated vesting schedule	5,444	4,065	13,574	10,839
Limited partnership units amortization	$ 8,470	$ 5,597	$ 22,986	$ 20,601