v3.26.3
Debt - Narrative (Details)
$ in Thousands, € in Millions
3 Months Ended 9 Months Ended
Jun. 18, 2026
USD ($)
Mar. 05, 2026
USD ($)
Jan. 15, 2026
USD ($)
Oct. 08, 2025
EUR (€)
Sep. 01, 2025
USD ($)
May 12, 2025
EUR (€)
Apr. 25, 2025
USD ($)
Mar. 20, 2025
EUR (€)
Mar. 13, 2025
EUR (€)
Jan. 29, 2025
EUR (€)
Sep. 30, 2026
USD ($)
item
property
Sep. 30, 2026
USD ($)
item
property
Sep. 30, 2026
EUR (€)
item
property
Sep. 30, 2025
USD ($)
Sep. 30, 2026
EUR (€)
property
item
Sep. 16, 2026
USD ($)
Jun. 15, 2026
EUR (€)
Jan. 13, 2026
USD ($)
Dec. 31, 2025
USD ($)
Oct. 31, 2025
USD ($)
Aug. 19, 2025
USD ($)
Jan. 30, 2025
property
Indebtedness                                            
Long-term debt                     $ 28,423,903 $ 28,423,903             $ 28,430,175      
Amount of debt redeemed                       9,728,917   $ 2,192,624                
The Mall Firenze and The Mall Sanremo                                            
Indebtedness                                            
Number of luxury outlets acquired | property                                           2
Simon Property Group, L.P.                                            
Indebtedness                                            
Long-term debt                     28,423,903 28,423,903             28,430,175      
Amount of debt redeemed                       9,728,917   $ 2,192,624                
Exchangeable Debt | Simon Property Group, L.P.                                            
Indebtedness                                            
Long-term debt                     32,000 32,000     € 28.2              
Amount of debt converted                       824,300 € 706.4                  
Amount of debt redeemed                       898,700 € 770.2                  
Mortgages | TRG                                            
Indebtedness                                            
Mortgage debt assumed                                       $ 3,100,000    
Unsecured Debt | Credit Facilities | Simon Property Group, L.P.                                            
Indebtedness                                            
Available borrowing capacity                     7,700,000 7,700,000                    
Maximum amount outstanding during period                       460,000                    
Credit facility, weighted average amount outstanding                       284,800                    
Letters of credit outstanding                     3,100 3,100                    
Unsecured Debt | Unsecured Term Loan Maturing March 20, 2029 | Simon Property Group, L.P.                                            
Indebtedness                                            
Long-term debt                     397,000 397,000     € 350.0              
Debt issued | €               € 350.0                            
Interest rate on debt (as a percent)               2.60%                            
Unsecured Debt | Unsecured Term Loan Maturing June 18, 2031 | Simon Property Group, L.P.                                            
Indebtedness                                            
Long-term debt                     460,000 460,000                    
Debt issued $ 460,000                                          
Interest rate on debt (as a percent) 4.02%                                          
Unsecured Debt | Credit Facility | Simon Property Group, L.P.                                            
Indebtedness                                            
Maximum borrowing capacity   $ 5,000,000                 5,000,000 $ 5,000,000                    
Additional borrowing capacity   1,000,000                                        
Optional expanded maximum borrowing capacity   $ 6,000,000                                        
Debt extension period   1 year                                        
Credit facility, amount repaid $ 460,000             € 376.0 € 18.0                          
Amount drawn             $ 155,000     € 376.0                        
Unsecured Debt | Credit Facility | Simon Property Group, L.P. | Fed Funds Effective Rate                                            
Indebtedness                                            
Interest rate (as a percent)                       0.50% 0.50%                  
Unsecured Debt | Credit Facility | Simon Property Group, L.P. | Adjusted Term One-Month SOFR                                            
Indebtedness                                            
Interest rate (as a percent)                       1.00% 1.00%                  
Unsecured Debt | Credit Facility | Simon Property Group, L.P. | Secured Overnight Financing Rate (SOFR)                                            
Indebtedness                                            
Interest rate (as a percent)                       0.65% 0.65%                  
Unsecured Debt | Credit Facility | Minimum | Simon Property Group, L.P.                                            
Indebtedness                                            
Facility fee (in percentage)                       0.10% 0.10%                  
Unsecured Debt | Credit Facility | Minimum | Simon Property Group, L.P. | Base Rate                                            
Indebtedness                                            
Interest rate (as a percent)                       0.00% 0.00%                  
Unsecured Debt | Credit Facility | Minimum | Simon Property Group, L.P. | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate                                            
Indebtedness                                            
Interest rate (as a percent)                       0.625% 0.625%                  
Unsecured Debt | Credit Facility | Maximum | Simon Property Group, L.P.                                            
Indebtedness                                            
Facility fee (in percentage)                       0.30% 0.30%                  
Unsecured Debt | Credit Facility | Maximum | Simon Property Group, L.P. | Base Rate                                            
Indebtedness                                            
Interest rate (as a percent)                       0.35% 0.35%                  
Unsecured Debt | Credit Facility | Maximum | Simon Property Group, L.P. | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate                                            
Indebtedness                                            
Interest rate (as a percent)                       1.35% 1.35%                  
Unsecured Debt | Supplemental Facility | Simon Property Group, L.P.                                            
Indebtedness                                            
Maximum borrowing capacity                     3,500,000 $ 3,500,000                    
Optional expanded maximum borrowing capacity                     4,500,000 $ 4,500,000                    
Credit facility, amount repaid | €       € 500.0                                    
Amount drawn | €           € 500.0                                
Unsecured Debt | Supplemental Facility | Simon Property Group, L.P. | Fed Funds Effective Rate                                            
Indebtedness                                            
Interest rate (as a percent)                       0.50% 0.50%                  
Unsecured Debt | Supplemental Facility | Simon Property Group, L.P. | Adjusted Term One-Month SOFR                                            
Indebtedness                                            
Interest rate (as a percent)                       1.00% 1.00%                  
Unsecured Debt | Supplemental Facility | Simon Property Group, L.P. | Secured Overnight Financing Rate (SOFR)                                            
Indebtedness                                            
Interest rate (as a percent)                       0.65% 0.65%                  
Unsecured Debt | Supplemental Facility | Minimum | Simon Property Group, L.P.                                            
Indebtedness                                            
Facility fee (in percentage)                       0.10% 0.10%                  
Unsecured Debt | Supplemental Facility | Minimum | Simon Property Group, L.P. | Base Rate                                            
Indebtedness                                            
Interest rate (as a percent)                       0.00% 0.00%                  
Unsecured Debt | Supplemental Facility | Minimum | Simon Property Group, L.P. | Secured Overnight Financing Rate (SOFR)                                            
Indebtedness                                            
Interest rate (as a percent)                       0.625% 0.625%                  
Unsecured Debt | Supplemental Facility | Maximum | Simon Property Group, L.P.                                            
Indebtedness                                            
Facility fee (in percentage)                       0.30% 0.30%                  
Unsecured Debt | Supplemental Facility | Maximum | Simon Property Group, L.P. | Base Rate                                            
Indebtedness                                            
Interest rate (as a percent)                       0.35% 0.35%                  
Unsecured Debt | Supplemental Facility | Maximum | Simon Property Group, L.P. | Secured Overnight Financing Rate (SOFR)                                            
Indebtedness                                            
Interest rate (as a percent)                       1.35% 1.35%                  
Unsecured Debt | Commercial Paper | Simon Property Group, L.P.                                            
Indebtedness                                            
Credit facility, amount outstanding                     755,000 $ 755,000                    
Maximum borrowing capacity                     2,000,000 2,000,000                    
Unsecured Debt | U.S Dollar Denominated Notes | Simon Property Group, L.P.                                            
Indebtedness                                            
Credit facility, amount outstanding                     $ 755,000 $ 755,000                    
Weighted average interest rate (as a percent)                     3.97% 3.97%     3.97%              
Unsecured Debt | Senior unsecured notes | Simon Property Group, L.P.                                            
Indebtedness                                            
Long-term debt                     $ 19,600,000 $ 19,600,000                    
Unsecured Debt | Senior Unsecured Notes 3.30% due 2026 | Simon Property Group, L.P.                                            
Indebtedness                                            
Interest rate on debt (as a percent)     3.30%                                      
Amount of debt redeemed     $ 800,000                                      
Unsecured Debt | Senior Unsecured Notes 4.375 due 2030 | Simon Property Group, L.P.                                            
Indebtedness                                            
Debt issued                                         $ 700,000  
Interest rate on debt (as a percent)                                         4.375%  
Unsecured Debt | Senior Unsecured Notes 5.125 due 2035 | Simon Property Group, L.P.                                            
Indebtedness                                            
Debt issued                                         $ 800,000  
Interest rate on debt (as a percent)                                         5.125%  
Unsecured Debt | Senior Unsecured Notes 3.50 due 2035 | Simon Property Group, L.P.                                            
Indebtedness                                            
Interest rate on debt (as a percent)         3.50%                                  
Amount of debt redeemed         $ 1,100,000                                  
Unsecured Debt | Senior Unsecured Notes 1.25% due 2025 | Simon Property Group, L.P.                                            
Indebtedness                                            
Amount of debt redeemed | €           € 500.0                                
Unsecured Debt | Senior Unsecured Notes Maturing January 2031 | Simon Property Group, L.P.                                            
Indebtedness                                            
Debt issued                                   $ 800,000        
Interest rate on debt (as a percent)                                   4.30%        
Unsecured Debt | Senior Unsecured Notes Maturing February 15, 2032 | Simon Property Group, L.P.                                            
Indebtedness                                            
Debt issued                               $ 400,000            
Interest rate on debt (as a percent)                               5.25%            
Unsecured Debt | Senior Unsecured Notes Maturing June 15, 2031 | Simon Property Group, L.P.                                            
Indebtedness                                            
Debt issued | €                                 € 500.0          
Interest rate on debt (as a percent)                                 3.65%          
Unsecured Debt | Senior Unsecured Notes Maturing October 1, 2036 | Simon Property Group, L.P.                                            
Indebtedness                                            
Debt issued                               $ 400,000            
Interest rate on debt (as a percent)                               5.65%            
Unsecured Debt | Senior Unsecured Notes Maturing November 30, 2026 | Simon Property Group, L.P.                                            
Indebtedness                                            
Long-term debt                     $ 750,000 $ 750,000                    
Interest rate on debt (as a percent)                     3.25% 3.25%     3.25%              
Secured Debt | Mortgages                                            
Indebtedness                                            
Long-term debt                     $ 7,400,000 $ 7,400,000             $ 8,200,000      
Amount of debt redeemed                     $ 540,000                      
Number of properties unencumbered | property                     2                      
Debt covenants                                            
Number of non-recourse mortgage notes under which the Company and subsidiaries are borrowers | item                       38 38                  
Number of properties pledged as collateral | property                       42 42                  
Number of cross-defaulted and cross-collateralized mortgage pools | item                     3 3     3              
Total number of properties pledged as collateral for cross defaulted and cross collateralized mortgages | property                     7 7     7