Commission and Fee Income and Underwriting Fee Income - Narrative (Details) $ in Millions |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2026
USD ($)
|
Dec. 31, 2025
USD ($)
|
|
| Disaggregation of Revenue [Line Items] | ||
| Contract asset after allowance for credit loss | $ 0.7 | $ 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 | |
| Apollo Group Holdings Limited | Syndicate 1969 | Related Party | ||
| Disaggregation of Revenue [Line Items] | ||
| Profit commission (in percent) | 0.175 | |
| Apollo Group Holdings Limited | Syndicate 1971 | Related Party | ||
| Disaggregation of Revenue [Line Items] | ||
| Profit commission (in percent) | 0.200 |