Quarterly report pursuant to Section 13 or 15(d)

NONCONTROLLING INTERESTS - Narrative (Details)

v3.7.0.1
NONCONTROLLING INTERESTS - Narrative (Details)
 3 Months Ended
Mar. 31, 2017
unit / shares
shares
OP units [Member] | NSA OP, LP [Member]  
Class of Stock [Line Items]  
Unit conversion ratio | unit / shares 1
Minimum conversion period 1 year
Redemptions of OP units for common shares (in shares) 1,077,074
OP units [Member] | NSA OP, LP [Member] | Self Storage Properties [Member]  
Class of Stock [Line Items]  
Issuance of units, (in shares) 174,694
OP units [Member] | DownREIT Partnership [Member]  
Class of Stock [Line Items]  
Unit conversion ratio | unit / shares 1
Minimum conversion period 5 years
Subordinated performance units [Member] | NSA OP, LP [Member]  
Class of Stock [Line Items]  
Unit conversion, lock out period 2 years
Subordinated performance units [Member] | NSA OP, LP [Member] | Self Storage Properties [Member]  
Class of Stock [Line Items]  
Issuance of units, (in shares) 47,332
Subordinated performance units [Member] | NSA OP, LP [Member] | Affiliate of Personal Mini [Member]  
Class of Stock [Line Items]  
Issuance of units, (in shares) 300,043
Subordinated performance units [Member] | DownREIT Partnership [Member]  
Class of Stock [Line Items]  
Unit conversion ratio | unit / shares 1
Minimum conversion period 5 years
LTIP units [Member]  
Class of Stock [Line Items]  
Issuance of units, (in shares) 206,841
LTIP units [Member] | NSA OP, LP [Member]  
Class of Stock [Line Items]  
Unit conversion ratio | unit / shares 1