Subsequent Events - Additional Information (Detail)
1 Months Ended 12 Months Ended
Feb. 24, 2022
USD ($)
ft²
State
StorageFacility
StorageProperty
Landparcel
StorageUnit
$ / shares
shares
Feb. 08, 2022
USD ($)
Mar. 17, 2021
USD ($)
Feb. 28, 2022
shares
Apr. 30, 2021
shares
Dec. 31, 2021
StorageFacility
State
shares
Dec. 31, 2020
shares
Subsequent Event [Line Items]              
Number Of Self Storage Units | StorageFacility           139  
Number of states located for self storage facilities | State           18  
Key Bank              
Subsequent Event [Line Items]              
Proceeds from line of credit | $     $ 451,000,000        
LTIPs | Performance Based Awards              
Subsequent Event [Line Items]              
Issuance of equity awards           148,387 130,638
Percentage of established target performance criteria           200.00%  
LTIPs | Performance Based Awards | Minimum              
Subsequent Event [Line Items]              
Percentage of established target performance criteria           0.00%  
LTIPs | Performance Based Awards | Maximum              
Subsequent Event [Line Items]              
Percentage of established target performance criteria           200.00%  
LTIPs | Performance Based Awards | Executive Officers              
Subsequent Event [Line Items]              
Issuance of equity awards         148,387    
LTIPs | Performance Based Awards | Executive Officers | Subsequent Event              
Subsequent Event [Line Items]              
Issuance of equity awards       113,400      
Percentage of established target performance criteria       200.00%      
Vesting period       3 years      
LTIPs | Performance Based Awards | Executive Officers | Minimum | Subsequent Event              
Subsequent Event [Line Items]              
Percentage of established target performance criteria       0.00%      
LTIPs | Performance Based Awards | Executive Officers | Maximum | Subsequent Event              
Subsequent Event [Line Items]              
Percentage of established target performance criteria       200.00%      
LTIPs | Time Based Awards              
Subsequent Event [Line Items]              
Issuance of equity awards           222,581 214,521
LTIPs | Time Based Awards | Executive Officers              
Subsequent Event [Line Items]              
Issuance of equity awards         222,581    
Vesting period         4 years    
LTIPs | Time Based Awards | Executive Officers | Subsequent Event              
Subsequent Event [Line Items]              
Issuance of equity awards       170,100      
Vesting period       4 years      
Algonquin Property | Subsequent Event              
Subsequent Event [Line Items]              
Consideration transferred | $   $ 19,000,000          
Algonquin Property | Subsequent Event | Credit Facility Revolver | Key Bank              
Subsequent Event [Line Items]              
Proceeds from line of credit | $   $ 19,000,000          
SSGT II Merger Agreement              
Subsequent Event [Line Items]              
Conversion of right to receive shares, description           will be converted into the right to receive 0.9118 shares of our Class A Shares  
Number of self storage facilities | StorageFacility 10            
Number Of Self Storage Units | StorageUnit 7,740            
Number of states located for self storage facilities | State 7            
Net Rentable Area | ft² 853,900            
Percentage of membership interest 50.00%            
SSGT II Merger Agreement | Subsequent Event              
Subsequent Event [Line Items]              
Number of self storage facilities | StorageFacility 10            
Number Of Self Storage Units | StorageUnit 7,740            
Number of states located for self storage facilities | State 7            
Net Rentable Area | ft² 853,900            
Percentage of membership interest 50.00%            
Remaining percentage of membership interest 50.00%            
Number of operating self storage property | StorageProperty 1            
Number of land parcels developed into self storage facilities | Landparcel 2            
SSGT II Merger Agreement | Subsequent Event | Termination Under Certain Other Circumstances Member              
Subsequent Event [Line Items]              
Termination payment | $ $ 5,200,000            
SSGT II Merger Agreement | Subsequent Event | Termination Arising out of the Go Shop              
Subsequent Event [Line Items]              
Termination payment | $ 2,600,000            
SSGT II Merger Agreement | Maximum | Subsequent Event              
Subsequent Event [Line Items]              
Customer expense reimbursement | $ $ 1,000,000            
SmartStop Common Stock | SSGT II Merger Agreement | Subsequent Event              
Subsequent Event [Line Items]              
Number of right to receive shares from conversion 0.9118            
SSGT II Common Stock | SSGT II Merger Agreement | Subsequent Event              
Subsequent Event [Line Items]              
Common Stock, par value | $ / shares $ 0.001