v3.25.3
Organization - Additional Information (Detail)
$ / shares in Units, $ in Thousands
 1 Months Ended 3 Months Ended 9 Months Ended 37 Months Ended
Oct. 01, 2025
ft²
StorageFacility
Property
Jul. 30, 2025
USD ($)
$ / shares
shares
May 01, 2025
shares
Apr. 03, 2025
USD ($)
shares
Apr. 01, 2025
$ / shares
shares
May 31, 2025
StorageProperty
Apr. 30, 2025
shares
Sep. 30, 2024
USD ($)
shares
Sep. 30, 2025
ft²
StorageUnit
State
StorageFacility
Property
$ / shares
shares
Sep. 30, 2024
USD ($)
shares
Jan. 31, 2017
shares
Jun. 12, 2025
$ / shares
shares
Mar. 20, 2025
$ / shares
shares
Mar. 12, 2025
$ / shares
Dec. 31, 2024
$ / shares
shares
May 14, 2024
shares
Nov. 30, 2016
USD ($)
Organization And Nature Of Operations [Line Items]                                  
Date of formation of company                 Jan. 08, 2013                
Number of self storage facilities | StorageProperty           2                      
Number of states located for self storage facilities | State                 20                
Net rentable area, primarily self storage space | ft²                 115,000                
Preferred stock, authorized                       50,000,000          
Preferred stock, authorized, par value | $ / shares                       $ 0.001          
Redemptions of common stock (in shares)   8,000                              
Redemptions of common stock, value | $   $ 300           $ 1   $ 1              
Redemption of common stock, purchase price | $ / shares   $ 35.63                              
Common Stock, par value | $ / shares                 $ 0.001     $ 0.001     $ 0.001    
Common Stock, shares authorized                 141,250,000     175,000,000     0    
Common stock shares without designation, authorized                       141,250,000          
Advisor, SS Toronto REIT Advisors, Inc., and SS Growth Advisor, LLC.                                  
Organization And Nature Of Operations [Line Items]                                  
Percentage of limited partnership interests                 94.00%                
SAM and Affiliates                                  
Organization And Nature Of Operations [Line Items]                                  
Percentage of Joint venture minority ownership                 6.00%                
Distribution Reinvestment Plan                                  
Organization And Nature Of Operations [Line Items]                                  
Common stock, value authorize | $                                 $ 100,900
Underwritten Public Offering [Member]                                  
Organization And Nature Of Operations [Line Items]                                  
Number of shares issued in offering         27,000,000                        
Initial price | $ / shares         $ 30                        
Gross proceeds from issuance of common stock | $       $ 931,500                          
Net proceeds from issuance of common stock | $       $ 875,600                          
Common Stock, par value | $ / shares         $ 0.001                        
Underwritten Public Offering [Member] | Officers and Directors                                  
Organization And Nature Of Operations [Line Items]                                  
Number of shares issued in offering             31,500                    
Over-Allotment Option [Member]                                  
Organization And Nature Of Operations [Line Items]                                  
Number of shares issued in offering       4,050,000                          
Minimum [Member]                                  
Organization And Nature Of Operations [Line Items]                                  
Common Stock, shares authorized                       900,000,000          
Maximum [Member]                                  
Organization And Nature Of Operations [Line Items]                                  
Common Stock, shares authorized                       225,000,000          
Class A Common stock                                  
Organization And Nature Of Operations [Line Items]                                  
NAV per share | $ / shares                           $ 58      
Common Stock, par value | $ / shares                 $ 0.001       $ 0.001   $ 0.001    
Common Stock, shares authorized                 31,250,000     31,250,000 225,000,000   350,000,000    
Class A Common stock | Distribution Reinvestment Plan                                  
Organization And Nature Of Operations [Line Items]                                  
Number of shares issued in offering     2,700,000               493,000,000            
Common Stock, shares authorized                               1,125,000  
Class A Common stock | Common Stock                                  
Organization And Nature Of Operations [Line Items]                                  
Redemptions of common stock (in shares)               137,511   327,122              
Redemptions of common stock, value | $               $ 1   $ 1              
Class T Common stock                                  
Organization And Nature Of Operations [Line Items]                                  
NAV per share | $ / shares                           $ 58      
Common Stock, par value | $ / shares                 $ 0.001       $ 0.001   $ 0.001    
Common Stock, shares authorized                 2,500,000     2,500,000 340,000,000   350,000,000    
Class T Common stock | Distribution Reinvestment Plan                                  
Organization And Nature Of Operations [Line Items]                                  
Number of shares issued in offering     300,000               73,000,000            
Common Stock, shares authorized                               125,000  
Class T Common stock | Common Stock                                  
Organization And Nature Of Operations [Line Items]                                  
Redemptions of common stock (in shares)               4,527   21,034              
Common Class A And Class T [Member]                                  
Organization And Nature Of Operations [Line Items]                                  
Common Stock, par value | $ / shares                         $ 0.001        
Common Stock, shares authorized                 565,000,000                
Managed REITS                                  
Organization And Nature Of Operations [Line Items]                                  
Number of self storage facilities | StorageFacility                 40,000                
Number of properties owned by Managed REITs which is operated by the company | Property                 49                
Number of self storage units | StorageUnit                 177                
Net rentable area, primarily self storage space | ft²                 4,400,000                
Argus Professional Storage Management, LLC | Subsequent Event [Member]                                  
Organization And Nature Of Operations [Line Items]                                  
Number of self storage facilities | StorageFacility 100,000                                
Number of properties owned by Managed REITs which is operated by the company | Property 225                                
Net rentable area, primarily self storage space | ft² 16,600,000