Real Estate Facilities - Additional Information (Detail)
$ in Millions
 12 Months Ended
Mar. 17, 2022
USD ($)
Mar. 11, 2022
USD ($)
Feb. 24, 2022
USD ($)
Feb. 23, 2022
USD ($)
Feb. 08, 2022
USD ($)
Jan. 31, 2022
USD ($)
Dec. 30, 2021
StorageFacility
Dec. 28, 2021
USD ($)
Oct. 19, 2021
USD ($)
StorageFacility
May 27, 2021
USD ($)
RealEstateVenture
Apr. 16, 2021
CAD ($)
StorageFacility
Mar. 17, 2021
State
StorageFacility
Mar. 11, 2021
USD ($)
Mar. 10, 2021
USD ($)
Nov. 10, 2020
USD ($)
State
StorageFacility
ft²
RealEstateVenture
Dec. 31, 2021
StorageFacility
State
Apr. 16, 2021
USD ($)
Business Acquisition [Line Items]                                  
Number of states located for self storage facilities | State                               18  
Number of operating real estate properties | StorageFacility                               5  
Number of development real estate properties | StorageFacility                               1  
Occupancy percentage                   95.00%              
Self Storage Facility in Phoenix, Arizona                                  
Business Acquisition [Line Items]                                  
Debt Instrument, Term                         6 months        
Self Storage Facility in Phoenix, Arizona | Mezzanine Loan                                  
Business Acquisition [Line Items]                                  
Debt Instrument, Face Amount                         $ 3,500,000 $ 3,500,000      
Debt Instrument, Interest Rate, Effective Percentage                         8.50% 8.50%      
Debt Instrument, Term                         6 months        
Self Storage Facility in Phoenix, Arizona | Extension Option Mezzanine Loan                                  
Business Acquisition [Line Items]                                  
Debt Instrument, Interest Rate, Effective Percentage                         9.25% 9.25%      
Debt Instrument, Term                         180 days 180 days      
Self Storage Facility in Phoenix, Arizona | Third Party Mortgage Loan on Property                                  
Business Acquisition [Line Items]                                  
Debt Instrument, Face Amount                         $ 9,000,000        
SmartStop OP                                  
Business Acquisition [Line Items]                                  
Investments                           $ 5,000,000.0      
SST VI OP                                  
Business Acquisition [Line Items]                                  
Number of self storage facilities | StorageFacility             2                    
SST VI OP | Mezzanine Loan                                  
Business Acquisition [Line Items]                                  
Debt Instrument, Face Amount                                 $ 2,100,000
SST VI OP | Self Storage Facility in Phoenix, Arizona                                  
Business Acquisition [Line Items]                                  
Payments to Acquire Property, Plant, and Equipment                         $ 16,000,000 $ 16,000,000      
Canada                                  
Business Acquisition [Line Items]                                  
Number of self storage real estate joint ventures | RealEstateVenture                             6    
SST IV Merger Agreement                                  
Business Acquisition [Line Items]                                  
Number of states located for self storage facilities | State                       9          
Number of self storage facilities | StorageFacility                       24          
SST IV Merger Agreement | Canada                                  
Business Acquisition [Line Items]                                  
Number of states located for self storage facilities | State                       9     9    
Number of self storage facilities | ft²                             24    
Number of self storage real estate joint ventures | RealEstateVenture                             6    
Number of operating real estate properties | StorageFacility                       3     3    
Number of development real estate properties | StorageFacility                       3     3    
Strategic Storage Trust IV, Inc.                                  
Business Acquisition [Line Items]                                  
Purchase price                             $ 286,028,173    
Oakville III Property                                  
Business Acquisition [Line Items]                                  
Number of self storage facilities purchased | StorageFacility                     1            
Purchase price                     $ 25.0            
Occupancy percentage                                 42.00%
Riverside III Property                                  
Business Acquisition [Line Items]                                  
Number of self storage facilities purchased | RealEstateVenture                   1              
Purchase price                   $ 10,700,000              
Lakewood Property                                  
Business Acquisition [Line Items]                                  
Number of self storage facilities purchased | StorageFacility                 1                
Purchase price                 $ 17,500,000                
Occupancy percentage                 91.30%                
Algonquin Property | Subsequent Event                                  
Business Acquisition [Line Items]                                  
Purchase price         $ 19,000,000                        
Occupancy percentage         72.40%                        
Portland Property                                  
Business Acquisition [Line Items]                                  
Purchase price               $ 15,000,000                  
Vancouver Property | Subsequent Event                                  
Business Acquisition [Line Items]                                  
Purchase price           $ 25,000,000                      
Sacramento Property | Subsequent Event                                  
Business Acquisition [Line Items]                                  
Purchase price       $ 25,800,000                          
Levittown and Newark Portfolio | Subsequent Event                                  
Business Acquisition [Line Items]                                  
Purchase price     $ 40,700,000                            
St. Johns Property | Subsequent Event                                  
Business Acquisition [Line Items]                                  
Purchase price $ 16,300,000                                
Chandler Property | Subsequent Event                                  
Business Acquisition [Line Items]                                  
Purchase price   $ 25,500,000                              
Class A Common stock                                  
Business Acquisition [Line Items]                                  
Conversion of right to receive shares, description                               converted into the right to receive 2.1875 Class A Shares  
Class A Common stock | Strategic Storage Trust IV, Inc.                                  
Business Acquisition [Line Items]                                  
Common stock issued                             $ 23,100,000