v3.26.3
Contracts Accounted for as Financial Guaranty Insurance - Additional Information (Details)
9 Months Ended 12 Months Ended
Sep. 30, 2026
Dec. 31, 2025
Guarantor Obligations [Line Items]    
Weighted average risk-free rates for U.S. dollar denominated financial guaranty insurance obligations 4.99% 3.93%
Minimum    
Guarantor Obligations [Line Items]    
Weighted average risk-free rates for U.S. dollar denominated financial guaranty insurance obligations 2.44% 1.93%
Maximum    
Guarantor Obligations [Line Items]    
Weighted average risk-free rates for U.S. dollar denominated financial guaranty insurance obligations 6.07% 5.35%
Foreign Currency Concentration Risk | Premiums Receivable | Premiums Receivable    
Guarantor Obligations [Line Items]    
Percentage of installment premiums denominated in currencies other than the U.S. dollar 65.00% 68.00%