v3.26.1
Commission and Fee Income and Underwriting Fee Income - Narrative (Details)
$ in Millions
6 Months Ended
Jun. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
Disaggregation of Revenue [Line Items]    
Contract asset after allowance for credit loss $ 1.0 $ 1.0
Apollo Group Holdings Limited | Managed Syndicates | Related Party    
Disaggregation of Revenue [Line Items]    
Agency fees from syndicates (in percent) 0.009  
Apollo Group Holdings Limited | SPA1925 | Related Party    
Disaggregation of Revenue [Line Items]    
Agency fees from syndicates (in percent) 0.010