v3.26.1
Compensation - Schedule of Activity Associated with Restricted Stock Units (Details) - Restricted Stock Units - USD ($)
$ / shares in Units, $ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Newmark Holdings, L.P.    
Restricted Stock Units    
Beginning balance (in shares) 9,676,773 10,977,725
Number of units, Granted (in shares) 2,021,891 3,023,455
Number of Settled units (delivered shares) (in shares) (2,281,275) (3,994,549)
Number of Units, Forfeited units (in shares) (174,980) (329,858)
Ending balance (in shares) 9,242,409 9,676,773
Weighted- Average Grant Date Fair Value Per Share    
Balance at the beginning of period (in dollars per share) $ 9.84 $ 8.91
Granted (in dollars per share) 15.14 11.84
Settled units (delivered shares) (in dollars per share) 9.57 8.80
Forfeited units (in dollars per share) 9.50 9.86
Balance at the end of period (in dollars per share) $ 11.07 $ 9.84
Fair Value Amount    
Balance at beginning of period $ 95,173 $ 97,771
Granted 30,615 35,802
Settled units (delivered shares) (21,842) (35,147)
Forfeited units (1,662) (3,253)
Balance at end of period $ 102,284 $ 95,173
Number of shares authorized to be repurchased (in shares) 34,279,000 57,886,000
Newmark Holdings, L.P. | Minimum    
Fair Value Amount    
Award vesting period 3 years  
Newmark Holdings, L.P. | Maximum    
Fair Value Amount    
Award vesting period 8 years  
BGC Holdings, L.P.    
Restricted Stock Units    
Beginning balance (in shares) 2,270 3,586
Number of units, Granted (in shares) 3,252 0
Number of Settled units (delivered shares) (in shares) (780) (1,316)
Number of Units, Forfeited units (in shares) 0 0
Ending balance (in shares) 4,742 2,270
Weighted- Average Grant Date Fair Value Per Share    
Balance at the beginning of period (in dollars per share) $ 3.96 $ 4.08
Granted (in dollars per share) 8.86 0
Settled units (delivered shares) (in dollars per share) 4.76 4.28
Forfeited units (in dollars per share) 0 0
Balance at the end of period (in dollars per share) $ 7.19 $ 3.96
Fair Value Amount    
Balance at beginning of period $ 9 $ 15
Granted 29 0
Settled units (delivered shares) (4) (6)
Forfeited units 0 0
Balance at end of period $ 34 $ 9
Number of shares authorized to be repurchased (in shares) 7,000 12,000
BGC Holdings, L.P. | Minimum    
Fair Value Amount    
Award vesting period 2 years  
BGC Holdings, L.P. | Maximum    
Fair Value Amount    
Award vesting period 5 years