Quarterly report [Sections 13 or 15(d)]

Debt - Narrative (Details)

v3.25.1
Debt - Narrative (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended 12 Months Ended
Aug. 31, 2024
Mar. 31, 2025
Mar. 31, 2024
Jun. 30, 2024
Dec. 31, 2024
Sep. 30, 2024
Sep. 19, 2024
Feb. 28, 2022
Debt Instrument [Line Items]                
Draw down on revolving credit facility   $ 574,056 $ 0          
Subject to mandatory redemption, period   15 years            
Accrued return paid   $ 62,946 $ 25,270          
Subsidiary Units Subject to Mandatory Redemption                
Debt Instrument [Line Items]                
Accrued interest   100     $ 100      
Historical costs of units cost and fair value of units   $ 3,300            
Implicit rate   9.80%            
Accrued return paid   $ 100            
Credit Agreement | Medium-Term Note | Secured Debt                
Debt Instrument [Line Items]                
Original principal $ 1,650,000              
Debt face amount           $ 1,700,000    
Principal outstanding   1,695,800     1,700,000      
Accrued interest   300     300      
Unamortized deferred issuance costs   26,700     $ 27,800      
Credit Agreement | Line of Credit | Revolving Credit Facility                
Debt Instrument [Line Items]                
Accrued interest   $ 1,000            
Basis spread on variable rate   2.50%     2.50%      
Deferred issuance cost   $ 9,100     $ 9,600      
Borrowing capacity   1,400,000     1,400,000      
Commitments available to be borrowed   975,600     1,399,700      
Draw down on revolving credit facility   424,100            
Reduction on revolving credit facility from undrawn letter of credit   300     300      
Unpaid commitment fees   $ 900   $ 1,200        
Credit Agreement | Line of Credit | Revolving Credit Facility | Minimum                
Debt Instrument [Line Items]                
Commitment fee on undrawn amounts   0.25%            
Credit Agreement | Line of Credit | Revolving Credit Facility | Maximum                
Debt Instrument [Line Items]                
Commitment fee on undrawn amounts   0.50%            
Senior Secured Notes Due February 2030 | Senior Secured Notes                
Debt Instrument [Line Items]                
Debt face amount               $ 400,000
Accrued interest   $ 2,900     7,300      
Unamortized deferred issuance costs   5,400     5,600      
Senior Secured Notes Due August 2032 | Senior Secured Notes                
Debt Instrument [Line Items]                
Debt face amount         600,000   $ 600,000  
Accrued interest   11,800     $ 20,000      
Debt instrument, face amount, percentage         99.50%      
Unamortized discounts and debt issuance costs, including discount   $ 21,200     $ 21,800