Annual report pursuant to Section 13 and 15(d)

RELATED PARTY TRANSACTIONS (Details)

v3.6.0.2
RELATED PARTY TRANSACTIONS (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2016
USD ($)
property
shares
Dec. 31, 2015
USD ($)
property
shares
Dec. 31, 2014
USD ($)
property
Related Party Transaction [Line Items]      
Affiliate payroll costs included in property operating expenses $ 64,798 $ 45,412 $ 27,913
Number of self storage properties acquired | property 107 58 83
Participating Regional Operator [Member] | Management [Member]      
Related Party Transaction [Line Items]      
Number of self storage properties acquired | property     16
Receivable balance netted against equity interest issued in business acquisition $ 1,400 $ 1,400 $ 5,200
Reimbursements received on assumed mortgages $ 1,400 $ 1,600  
Units issued upon reimbursement of assumed mortgages | shares 67,832 85,130  
Bridge loan agreement   $ 5,300  
Related party loan, weighted average fixed rate   3.30%  
Supervisory and Administrative Fee Agreement [Member] | Participating Regional Operator [Member] | Management [Member]      
Related Party Transaction [Line Items]      
Supervisory and administrative fees included in general and administrative expenses $ 11,000 $ 7,600 4,500
Supervisory and Administrative Fee Agreement [Member] | Participating Regional Operator [Member] | Minimum [Member] | Management [Member]      
Related Party Transaction [Line Items]      
Supervisory and administrative fee, percent of gross revenues 5.00%    
Supervisory and Administrative Fee Agreement [Member] | Participating Regional Operator [Member] | Maximum [Member] | Management [Member]      
Related Party Transaction [Line Items]      
Supervisory and administrative fee, percent of gross revenues 6.00%    
Affiliate Payroll Services [Member] | Participating Regional Operator [Member] | Management [Member]      
Related Party Transaction [Line Items]      
Affiliate payroll costs included in property operating expenses $ 19,400 13,400 8,400
Acquisition Costs [Member] | Due Diligence Costs [Member] | Participating Regional Operator [Member] | Management [Member]      
Related Party Transaction [Line Items]      
Fees and expenses $ 1,100 $ 600 $ 200