Compensation - Limited Partnership Units with a Post-Termination Payout (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
BGC Holdings, L.P.
Share-based Compensation Arrangement by Share-based Payment Award
Notional value	$ 158,594	$ 144,045
Estimated fair value of the post-termination payout	$ 54,950	$ 42,706
Outstanding limited partnership units (in shares)	0	44,928
NEWMARK Group Inc Parent
Share-based Compensation Arrangement by Share-based Payment Award
Outstanding limited partnership units (in shares)	16,704,405	14,277,213
Outstanding limited partnership units - unvested (in dollars per share)	4,856,908	2,155,668