v3.25.3
Summary of Significant Accounting Policies - Additional Information (Detail)
 3 Months Ended 9 Months Ended
Oct. 01, 2025
USD ($)
Property
Sep. 30, 2025
USD ($)
Sep. 30, 2024
USD ($)
Sep. 30, 2025
USD ($)
Segment
Trademark
Sep. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
Aug. 07, 2024
$ / shares
Aug. 06, 2024
$ / shares
Nov. 01, 2023
$ / shares
Summary Of Significant Accounting Policies [Line Items]                  
Payments to acquire intangible assets       $ 13,000,000 $ 1,800,000        
Asset acquisition-related transaction costs   $ 400,000 $ 100,000 800,000 100,000        
Impairment losses of real property assets recognized       0          
Indefinite lived trademark   15,700,000   15,700,000   $ 15,700,000      
Intangible assets, net of accumulated amortization   13,340,000   13,340,000   6,766,000      
Allowance for doubtful accounts   700,000   700,000   800,000      
Gross amounts of lease intangibles   99,600,000   99,600,000   86,400,000      
Accumulated amortization   86,200,000   $ 86,200,000   79,600,000      
Maximum annual contributions per employee, percentage       100.00%          
Gains (losses) on exchange rate changes in equity investments recorded in other income (expense)   $ 4,400,000 200,000 $ 8,000,000 (1,500,000)        
Investment, Type [Extensible Enumeration]   Real Estate Investment   Real Estate Investment          
Minimum percentage of ordinary taxable income to be distributed to stockholders       90.00%          
Employer matching contribution, percent       100.00%          
Employer matching contribution, percent of match       4.00%          
Number of reportable business segments | Segment       2          
Rental Income | Geographic Concentration Risk | Florida                  
Summary Of Significant Accounting Policies [Line Items]                  
Concentration Risk Percentage1       21.00%          
Rental Income | Geographic Concentration Risk | California                  
Summary Of Significant Accounting Policies [Line Items]                  
Concentration Risk Percentage1       21.00%          
Rental Income | Geographic Concentration Risk | Greater Toronto Area of Canada                  
Summary Of Significant Accounting Policies [Line Items]                  
Concentration Risk Percentage1       9.00%          
Revolving Credit Facility                  
Summary Of Significant Accounting Policies [Line Items]                  
Debt issuance cost, gross   $ 8,300,000   $ 8,300,000   9,400,000      
Accumulated amortization of debt issuance costs   4,300,000   4,300,000   2,600,000      
Non Revolving Debt                  
Summary Of Significant Accounting Policies [Line Items]                  
Debt issuance cost, gross   7,400,000   7,400,000   6,400,000      
Accumulated amortization of debt issuance costs   3,000,000   3,000,000   3,000,000      
Self Storage                  
Summary Of Significant Accounting Policies [Line Items]                  
Total estimated future amortization expense of intangible assets, year 2025   3,200,000   3,200,000          
Total estimated future amortization expense of intangible assets, year 2026   9,000,000   9,000,000          
Total estimated future amortization expense of intangible assets, year 2027   500,000   500,000          
Total estimated future amortization expense of intangible assets, year 2028   100,000   100,000          
Total estimated future amortization expense of intangible assets, thereafter   600,000   600,000          
Intangible assets, net of accumulated amortization   13,400,000   $ 13,400,000          
Weighted-average amortization period on remaining intangible assets       10 months 15 days          
Minimum                  
Summary Of Significant Accounting Policies [Line Items]                  
Estimated useful life       3 years          
Maximum                  
Summary Of Significant Accounting Policies [Line Items]                  
Estimated useful life       5 years          
Strategic Storage Trademark                  
Summary Of Significant Accounting Policies [Line Items]                  
Indefinite lived trademark   15,700,000   $ 15,700,000   $ 15,700,000      
Argus Professional Storage Management, LLC                  
Summary Of Significant Accounting Policies [Line Items]                  
Asset acquisition-related transaction costs   100,000   $ 200,000          
Number of properties severely flooded | Property 225                
Argus Professional Storage Management, LLC | Subsequent Event                  
Summary Of Significant Accounting Policies [Line Items]                  
Asset acquisition-related transaction costs $ 8,500,000                
Self Administration Transaction                  
Summary Of Significant Accounting Policies [Line Items]                  
Number of trademarks acquired | Trademark       2          
SST VI                  
Summary Of Significant Accounting Policies [Line Items]                  
Offering price | $ / shares             $ 10   $ 9.3
SST VI | Class A Common stock                  
Summary Of Significant Accounting Policies [Line Items]                  
Offering price | $ / shares             10   10
SST VI | Class C Common stock                  
Summary Of Significant Accounting Policies [Line Items]                  
Offering price | $ / shares             10    
SST VI | Common Class Y and Z shares                  
Summary Of Significant Accounting Policies [Line Items]                  
Offering price | $ / shares             10    
SST VI | Maximum | Class A Common stock                  
Summary Of Significant Accounting Policies [Line Items]                  
Offering price | $ / shares             $ 10   $ 10
SST VI OP | Class C Common stock                  
Summary Of Significant Accounting Policies [Line Items]                  
Share Price | $ / shares               $ 9.3  
Operating Expense                  
Summary Of Significant Accounting Policies [Line Items]                  
Advertising costs   1,500,000 1,300,000 $ 4,300,000 4,000,000        
General and Administrative Expense                  
Summary Of Significant Accounting Policies [Line Items]                  
Advertising costs   $ 500,000 $ 700,000 $ 1,600,000 $ 1,700,000