Annual report pursuant to Section 13 and 15(d)

SELF STORAGE PROPERTY ACQUISITIONS AND DISPOSITIONS - Pro Forma Information (Details)

v3.6.0.2
SELF STORAGE PROPERTY ACQUISITIONS AND DISPOSITIONS - Pro Forma Information (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2016
USD ($)
property
Dec. 31, 2015
USD ($)
property
Dec. 31, 2014
USD ($)
property
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]      
Pro forma revenue $ 234,525 $ 204,580 $ 127,943
Pro forma net income (loss) $ 40,209 $ (7,906) $ (2,220)
Number of self storage properties acquired | property 107 58 83
Acquisition costs $ 6,546 $ 4,765 $ 9,558
2016 Acquisitions [Member]      
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]      
Pro forma revenue 35,479 61,199 0
Pro forma net income (loss) $ 15,343 (23,105) 0
Number of businesses acquired for which pro forma financial information is available | property 100    
Number of self storage properties acquired | property 107    
Number of businesses acquired for which pro forma financial information is not available | property 7    
2015 Acquisitions [Member]      
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]      
Pro forma revenue $ 0 9,462 22,596
Pro forma net income (loss) 0 $ 10,403 (7,258)
Number of businesses acquired for which pro forma financial information is available | property   42  
Number of self storage properties acquired | property   58  
Number of businesses acquired for which pro forma financial information is not available | property   16  
2014 Acquisitions [Member]      
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]      
Pro forma revenue 0 $ 0 28,377
Pro forma net income (loss) 0 0 21,395
Consolidated Entities Excluding Acquirees [Member]      
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]      
Pro forma revenue 199,046 133,919 76,970
Pro forma net income (loss) $ 24,866 $ 4,796 $ (16,357)
Credit Facility [Member] | Line of Credit [Member] | Revolving line of credit [Member]      
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]      
Effective interest rate 2.17% 2.03% 2.66%