Quarterly report pursuant to Section 13 or 15(d)

RELATED PARTY TRANSACTIONS (Details)

v3.21.2
RELATED PARTY TRANSACTIONS (Details)
$ in Thousands
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2021
USD ($)
property
Mar. 31, 2021
USD ($)
property
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
property
shares
Jun. 30, 2020
USD ($)
Dec. 31, 2020
property
tranche
Related Party Transaction [Line Items]            
Payroll and related costs reimbursed to the PROs by the Company $ 36,654   $ 30,257 $ 71,258 $ 60,849  
Number of properties acquired | property 20 23   43    
Consideration in acquisition transaction $ 269,393 $ 165,963   $ 435,356    
Value of OP Equity 24,102 $ 22,897   46,999    
Supervisory and Administrative Fee Agreement | Management | Participating Regional Operator (PRO)            
Related Party Transaction [Line Items]            
Supervisory and administrative fees paid to the PROs 4,900   3,500 $ 9,100 8,800  
Supervisory and Administrative Fee Agreement | Management | Participating Regional Operator (PRO) | Minimum            
Related Party Transaction [Line Items]            
Supervisory and administrative fee agreement of gross revenue, percent       5.00%    
Supervisory and Administrative Fee Agreement | Management | Participating Regional Operator (PRO) | Maximum            
Related Party Transaction [Line Items]            
Supervisory and administrative fee agreement of gross revenue, percent       6.00%    
Payroll Services | Management | Participating Regional Operator (PRO)            
Related Party Transaction [Line Items]            
Payroll and related costs reimbursed to the PROs by the Company 6,600   5,500 $ 13,000 14,300  
Due Diligence Costs | Management | Participating Regional Operator (PRO)            
Related Party Transaction [Line Items]            
Due diligence expenses payable to the PROs $ 200   $ 100 $ 500 $ 200  
Self storage property purchase from affiliate of trustee | Affiliated entity            
Related Party Transaction [Line Items]            
Number of properties acquired | property       1   1
Number of earnout tranches | tranche           3
Consideration in acquisition transaction       $ 8,800    
Self storage property purchase from affiliate of trustee | Affiliated entity | Six month tranche            
Related Party Transaction [Line Items]            
Earnout performance periods           6 months
Self storage property purchase from affiliate of trustee | Affiliated entity | 12 month tranche            
Related Party Transaction [Line Items]            
Earnout performance periods           12 months
Consideration in acquisition transaction       $ 2,000    
Self storage property purchase from affiliate of trustee | Affiliated entity | 18 month tranche            
Related Party Transaction [Line Items]            
Earnout performance periods           18 months
OP units | Self storage property purchase from affiliate of trustee | Affiliated entity | Mr. J. Timothy Warren            
Related Party Transaction [Line Items]            
Number of OP Units in acquisition (in shares) | shares       29,123    
Value of OP Equity       $ 1,100    
OP units | Self storage property purchase from affiliate of trustee | Affiliated entity | Mr. J. Timothy Warren | 12 month tranche            
Related Party Transaction [Line Items]            
Number of OP Units in acquisition (in shares) | shares       13,105    
Value of OP Equity       $ 600