Quarterly report pursuant to Section 13 or 15(d)

RELATED PARTY TRANSACTIONS (Details)

v3.20.2
RELATED PARTY TRANSACTIONS (Details)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2020
USD ($)
property
Jun. 30, 2020
USD ($)
property
Mar. 31, 2020
USD ($)
property
Sep. 30, 2019
USD ($)
Sep. 30, 2020
USD ($)
property
shares
Sep. 30, 2019
USD ($)
Related Party Transaction [Line Items]            
Payroll and related costs reimbursed to the PROs by the Company $ 31,546     $ 28,988 $ 92,395 $ 82,635
Number of properties acquired | property 4 4 36   44  
Consideration in acquisition transaction $ 23,804 $ 36,247 $ 222,773   $ 282,824  
Value of OP Equity 3,427 $ 5,842 $ 7,217   16,486  
Supervisory and Administrative Fee Agreement | Management | Participating Regional Operator (PRO)            
Related Party Transaction [Line Items]            
Supervisory and administrative fees paid to the PROs 3,700     5,200 $ 12,500 14,800
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 $ 5,700     8,100 $ 20,000 23,800
Due Diligence Costs | Management | Participating Regional Operator (PRO)            
Related Party Transaction [Line Items]            
Due diligence expenses payable to the PROs       $ 100 $ 200 $ 700
Self storage property purchase from affiliate of executives | Affiliated entity            
Related Party Transaction [Line Items]            
Number of properties acquired | property         1  
Consideration in acquisition transaction         $ 7,500  
Self storage property purchase from affiliate of trustee | Affiliated entity            
Related Party Transaction [Line Items]            
Number of properties acquired | property         1  
Consideration in acquisition transaction         $ 6,600  
OP units | Self storage property purchase from affiliate of executives | Affiliated entity | Mr. Arlen Nordhagen            
Related Party Transaction [Line Items]            
Number of OP Units in acquisition (in shares) | shares         58,376  
Value of OP Equity         $ 1,500  
OP units | Self storage property purchase from affiliate of executives | Affiliated entity | Mr. David Cramer            
Related Party Transaction [Line Items]            
Number of OP Units in acquisition (in shares) | shares         29,689  
Value of OP Equity         $ 700  
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         15,512  
Value of OP Equity         $ 400