v3.26.1
Borrowings - Narrative (Details)
1 Months Ended 3 Months Ended
Aug. 31, 2025
USD ($)
Aug. 31, 2021
USD ($)
Mar. 31, 2026
USD ($)
day
Sep. 30, 2025
USD ($)
Sep. 30, 2024
USD ($)
Apr. 22, 2026
USD ($)
Dec. 31, 2025
USD ($)
Jun. 30, 2025
USD ($)
Nov. 30, 2024
USD ($)
Schedule of Borrowings [Line Items]                  
Total payments due     $ 1,951,762,000       $ 1,860,774,000    
Convertible senior notes                  
Schedule of Borrowings [Line Items]                  
Total payments due     $ 1,687,794,000       1,687,794,000    
Conversion price maximum threshold     130.00%            
Trading days | day     20            
Consecutive trading days | day     30            
Redemption price (in percent)   100.00% 100.00%            
Accrued interest     $ 6,200,000       0    
Convertible senior notes | Conversion Period One                  
Schedule of Borrowings [Line Items]                  
Conversion price maximum threshold     130.00%            
Trading days | day     20            
Consecutive trading days | day     30            
Convertible senior notes | Conversion Period Two                  
Schedule of Borrowings [Line Items]                  
Trading days | day     5            
Consecutive trading days | day     5            
Percentage of the last reported sale price     98.00%            
Risk retention financing facility | Secured debt                  
Schedule of Borrowings [Line Items]                  
Aggregate principal amount               $ 100,000,000.0  
Total payments due     $ 80,661,000       $ 75,647,000    
Securities loaned, fair value of collateral     $ 80,400,000            
Weighted average interest rate     0.40%            
Risk retention financing facility | Secured debt | Variable Interest Entity, Primary Beneficiary | Consolidated securitization                  
Schedule of Borrowings [Line Items]                  
Securities loaned, fair value of collateral     $ 2,100,000            
Risk retention financing facility | Secured debt | Notes receivable and residual certificates (at fair value)                  
Schedule of Borrowings [Line Items]                  
Securities loaned, fair value of collateral     $ 78,300,000            
Risk retention financing facility | Secured debt | Subsequent Event                  
Schedule of Borrowings [Line Items]                  
Aggregate principal amount           $ 200,000,000.0      
2026 Notes | Convertible senior notes                  
Schedule of Borrowings [Line Items]                  
Aggregate principal amount   $ 661,300,000              
Stated interest rate   0.25%              
Repurchase amount $ 232,600,000       $ 334,200,000        
Additional repurchased amount         27,900,000        
Gain (loss) on extinguishment of debt       $ 7,200,000 33,400,000        
Gross debt issuance cost   $ 15,700,000              
Effective interest rate   0.70%              
2029 Notes | Convertible senior notes                  
Schedule of Borrowings [Line Items]                  
Aggregate principal amount         $ 431,300,000        
Stated interest rate         2.00%        
Proceeds from convertible notes issuance, net of debt issuance costs paid to lender         $ 302,400,000        
Gross debt issuance cost         $ 10,400,000        
Effective interest rate         2.50%        
2030 Notes | Convertible senior notes                  
Schedule of Borrowings [Line Items]                  
Aggregate principal amount                 $ 500,000,000.0
Stated interest rate                 1.00%
Gross debt issuance cost                 $ 11,800,000
Effective interest rate                 1.40%
2032 Notes | Convertible senior notes                  
Schedule of Borrowings [Line Items]                  
Aggregate principal amount $ 690,000,000.0                
Stated interest rate 0.00%                
Proceeds from convertible notes issuance, net of debt issuance costs paid to lender $ 224,200,000                
Gross debt issuance cost $ 14,400,000                
Effective interest rate 0.30%