v3.26.3
Borrowings - Narrative (Details) - USD ($)
$ in Thousands
9 Months Ended
Aug. 31, 2026
Jul. 27, 2026
May 15, 2026
May 12, 2026
Feb. 18, 2025
Jan. 31, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Jun. 13, 2025
Line of Credit Facility [Line Items]                    
Short-term borrowings             $ 898,729   $ 498,415  
Repayment of unsecured debt             $ 498,851 $ 500,000    
Vertical risk retention interest             5.00%      
Uncommitted federal funds             $ 125,000      
Lendable value of collateral             3,300,000   2,500,000  
Unsecured borrowings                    
Line of Credit Facility [Line Items]                    
Short-term borrowings             0   498,415  
Line of credit                    
Line of Credit Facility [Line Items]                    
Short-term borrowings             0   $ 0  
Facility maximum borrowing capacity   $ 2,000,000               $ 2,500,000
Line of credit facility, interest holding percentage   100.00%                
Senior Unsecured Notes Due January 31, 2030 | Unsecured borrowings                    
Line of Credit Facility [Line Items]                    
Notes issued           $ 500,000        
Debt instrument, interest rate, stated percentage           6.50%        
Debt instrument, issuance price, percentage           99.78%        
Unsecured debt             494,000      
Senior Unsecured Notes Due October 29, 2025 | Unsecured borrowings                    
Line of Credit Facility [Line Items]                    
Debt instrument, interest rate, stated percentage         4.20%          
Repayments of long-term debt         $ 500,000          
Debt instrument, redemption price, percentage         100.00%          
Gain (loss) on extinguishment of debt         $ (1,000)          
Senior Unsecured Notes Due November 2, 2026 | Unsecured borrowings                    
Line of Credit Facility [Line Items]                    
Notes issued     $ 500,000              
Debt instrument, interest rate, stated percentage     6.495%              
Debt instrument, issuance price, percentage     100.00%              
Short-term borrowings             494,000      
2026 Senior Notes                    
Line of Credit Facility [Line Items]                    
Gain (loss) on extinguishment of debt             1,000      
Repurchased principal amount     $ 52,000              
2026 Senior Notes | Unsecured borrowings                    
Line of Credit Facility [Line Items]                    
Debt instrument, interest rate, stated percentage       3.125%            
Repurchased principal amount       $ 500,000            
Repayment of unsecured debt       447,000            
Fair value of repurchased amount       $ 448,000            
Percent of debt fair value       99.58%            
ABCP borrowings | Line of credit                    
Line of Credit Facility [Line Items]                    
Line of credit facility, revolving period   1 year                
Line of credit facility, amortization period   1 year                
Line of credit facility, expiration period   2 years                
Secured Warehouse Facility | Line of credit                    
Line of Credit Facility [Line Items]                    
Short-term borrowings             $ 900,000      
Weighted-average rate             4.75%      
Borrowing capacity available             $ 600,000      
Secured Warehouse Facility | Line of credit | Commercial paper rate                    
Line of Credit Facility [Line Items]                    
Variable interest rate spread 1.10%                  
Secured Warehouse Facility | Line of credit | SOFR                    
Line of Credit Facility [Line Items]                    
Variable interest rate spread 1.10%                  
Secured Warehouse Facility | Line of credit | Debt Instrument, Borrowing Period One                    
Line of Credit Facility [Line Items]                    
Facility maximum borrowing capacity $ 1,500,000                  
Secured Warehouse Facility | Line of credit | Debt Instrument, Borrowing Period Two                    
Line of Credit Facility [Line Items]                    
Facility maximum borrowing capacity $ 500,000