v3.25.2
Borrowings - Narrative (Details) - USD ($)
Jun. 30, 2025
Feb. 23, 2024
Feb. 15, 2024
Nov. 21, 2023
Sep. 29, 2023
Jun. 28, 2023
Feb. 24, 2023
May 25, 2022
Sep. 30, 2024
Jul. 23, 2024
Apr. 26, 2024
Nov. 14, 2023
Line of Credit Facility [Line Items]                        
Derivative interest rate (as a percent)                   6.50%   8.40%
Floating interest rate (as a percent)                   2.5954%   4.0405%
Notional amount                   $ 400,000,000   $ 350,000,000
Line of Credit                        
Line of Credit Facility [Line Items]                        
Aggregate amount $ 2,735,000,000               $ 2,685,000,000      
Unsecured Notes                        
Line of Credit Facility [Line Items]                        
Debt instrument, face amount 750,000,000.0               750,000,000.0      
ING Credit Agreement | Line of Credit                        
Line of Credit Facility [Line Items]                        
Aggregate amount $ 1,235,000,000               1,185,000,000      
Unused capacity, commitment fee (as a percent) 0.375%                      
Accordion feature, increase limit               $ 1,750,000,000        
Accordion feature, increase limit, percentage of shareholders' equity (as a percent)               150.00%        
ING Credit Agreement | Line of Credit | Secured Overnight Financing Rate (SOFR) | External Credit Rating, Investment Grade                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent) 1.875%                      
ING Credit Agreement | Line of Credit | Base Rate | External Credit Rating, Investment Grade                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent) 0.875%                      
ING Credit Agreement | Line of Credit | Alternative Base Rate | External Credit Rating, Investment Grade                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent) 0.10%                      
ING Credit Agreement | Line of Credit | Federal Funds Effective Rate                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)           0.50%   0.50%        
ING Credit Agreement | Line of Credit | Overnight Bank Funding Rate                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)           0.50%   0.50%        
ING Credit Agreement | Letter of Credit                        
Line of Credit Facility [Line Items]                        
Aggregate amount $ 25,000,000                      
IING Credit Agreement | Secured Overnight Financing Rate (SOFR)                        
Line of Credit Facility [Line Items]                        
Interest rate (as a percent) 1.75%                      
IING Credit Agreement | Base Rate                        
Line of Credit Facility [Line Items]                        
Interest rate (as a percent) 0.75%                      
IING Credit Agreement | Line of Credit | Secured Overnight Financing Rate (SOFR) | External Credit Rating, Investment Grade                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent) 0.10%                      
JPM SPV Facility | Line of Credit                        
Line of Credit Facility [Line Items]                        
Aggregate amount $ 500,000,000.0           $ 500,000,000   500,000,000.0      
Accordion feature, increase limit             $ 1,000,000,000          
Tenor period (in months)             3 months          
JPM SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR)                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)             2.50%          
SMBC SPV Facility | Line of Credit                        
Line of Credit Facility [Line Items]                        
Aggregate amount 150,000,000.0       $ 150,000,000       150,000,000.0      
Interest rate (as a percent)         0.75%              
Line of credit facility, unused capacity, percentage threshold (as a percent)         0.50%              
SMBC SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario One | Minimum                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)         2.45%              
SMBC SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario One | Maximum | Collateral Credit Facility                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)         3.00%              
SMBC SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario Two                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)         1.00%              
SMBC SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario Two | Minimum                        
Line of Credit Facility [Line Items]                        
Debt instrument, additional basis spread, variable rate (as a percent)         1.45%              
SMBC SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario Two | Maximum | Collateral Credit Facility                        
Line of Credit Facility [Line Items]                        
Debt instrument, additional basis spread, variable rate (as a percent)         2.00%              
SMBC SPV Facility | Line of Credit | Base Rate | Interest Rate Scenario Two                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)         0.00%              
SMBC SPV Facility | Line of Credit | Federal Funds Effective Rate                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)         50.00%              
CIBC SPV Facility | Line of Credit                        
Line of Credit Facility [Line Items]                        
Aggregate amount 350,000,000.0     $ 150,000,000         350,000,000.0   $ 350,000,000  
Unused capacity, commitment fee (as a percent)       0.50%                
Accordion feature, increase limit       $ 500,000,000                
CIBC SPV Facility | Line of Credit | Interest Rate Scenario Two                        
Line of Credit Facility [Line Items]                        
Debt instrument, additional basis spread, variable rate (as a percent)       0.95%                
CIBC SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario One                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)       1.95%                
CIBC SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario Two                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)       1.00%                
CIBC SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario Three                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)       2.00%                
CIBC SPV Facility | Line of Credit | Base Rate | Interest Rate Scenario Two                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)       0.00%                
CIBC SPV Facility | Line of Credit | Federal Funds Effective Rate                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)       0.50%                
DBNY SPV Facility | Line of Credit                        
Line of Credit Facility [Line Items]                        
Aggregate amount 300,000,000.0   $ 300,000,000           300,000,000.0      
Cost of funds rate, floor (as a percent)     0.25%                  
Borrowing capacity, increase limit     $ 1,000,000,000                  
Borrowing capacity, increase limit, six-month anniversary     $ 400,000,000                  
DBNY SPV Facility | Line of Credit | Cost of Funds Rate | Interest Rate Scenario One                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)     2.40%                  
DBNY SPV Facility | Line of Credit | Cost of Funds Rate | Interest Rate Scenario Two                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)     3.05%                  
DBNY SPV Facility | Line of Credit | Cost of Funds Rate | Interest Rate Scenario Three                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)     2.00%                  
MS SPV Facility | Line of Credit                        
Line of Credit Facility [Line Items]                        
Aggregate amount $ 200,000,000.0 $ 200,000,000             $ 200,000,000.0      
MS SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario One                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)   2.35%                    
MS SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario Two                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)   2.85%                    
MS SPV Facility | Line of Credit | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario Three                        
Line of Credit Facility [Line Items]                        
Debt instrument, basis spread, variable rate (as a percent)   2.00%                    
Notes due 2028 | Unsecured Notes                        
Line of Credit Facility [Line Items]                        
Debt instrument, face amount                       $ 350,000,000
Debt interest rate (as a percent)                       8.40%
Notes Due 2029 | Unsecured Notes                        
Line of Credit Facility [Line Items]                        
Debt instrument, face amount                   $ 400,000,000    
Debt interest rate (as a percent)                   6.50%