v3.26.1
Notes Payable - Homebuilding Textuals (Details) - USD ($)
$ in Millions
6 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Sep. 30, 2025
Debt Instrument [Line Items]      
Letters of Credit Outstanding, Amount $ 262.7    
Notes payable 6,563.8   $ 5,965.5
HomeBuildingOps      
Debt Instrument [Line Items]      
Line of Credit Facility, Current Borrowing Capacity 3,295.0 $ 2,305.0  
Line of Credit Facility, Maximum Borrowing Capacity $ 4,000.0    
Letters of credit, sublimit borrowing capacity, as a percentage 100.00%    
Borrowings outstanding on revolving credit facility $ 250.0   0.0
Letters of Credit Outstanding, Amount 219.8    
Line of Credit Facility, Remaining Borrowing Capacity 2,825.0    
Authorized Repurchase Of Debt Securities 500.0    
Debt Repurchase Authorization Remaining 500.0    
Notes payable $ 3,427.1   3,154.4
Line of Credit Facility, Interest Rate at Period End 4.50%    
HomeBuildingOps | Senior Notes      
Debt Instrument [Line Items]      
Notes payable $ 3,000.0    
HomeBuildingOps | Credit Facility Maturing December 18, 2029      
Debt Instrument [Line Items]      
Line of Credit Facility, Current Borrowing Capacity $ 2,017.5    
Line of Credit Facility, Expiration Date Mar. 27, 2031    
HomeBuildingOps | Credit Facility Maturing October 28, 2027      
Debt Instrument [Line Items]      
Line of Credit Facility, Current Borrowing Capacity $ 265.0    
Line of Credit Facility, Expiration Date Oct. 28, 2027    
HomeBuildingOps | Credit Facility Maturing March 27, 2029      
Debt Instrument [Line Items]      
Line of Credit Facility, Current Borrowing Capacity $ 1,012.5    
Line of Credit Facility, Expiration Date Mar. 27, 2029    
Rental      
Debt Instrument [Line Items]      
Line of Credit Facility, Current Borrowing Capacity $ 1,050.0    
Line of Credit Facility, Maximum Borrowing Capacity $ 2,000.0    
Letters of credit, sublimit borrowing capacity, as a percentage 50.00%    
Borrowings outstanding on revolving credit facility $ 865.0   600.0
Letters of Credit Outstanding, Amount 0.0    
Line of Credit Facility, Remaining Borrowing Capacity 185.0    
Notes payable $ 865.0   $ 600.0
Line of Credit Facility, Interest Rate at Period End 5.40%