Quarterly report pursuant to Section 13 or 15(d)

EARNINGS PER SHARE - Basic and Diluted Earnings per Share (Details)

v3.3.0.814
EARNINGS PER SHARE - Basic and Diluted Earnings per Share (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Net income (loss) $ 2,109 $ (5,025) $ (569) $ (13,986)
Net loss attributable to noncontrolling interests 2,263 5,025 8,405 13,986
Net income (loss) attributable to National Storage Affiliates Trust 4,372 0 7,836 0
Distributed and undistributed earnings allocated to participating securities (3) 0 (6) 0
Net income (loss) attributable to common shareholders - basic 4,369 0 7,830 0
Effect of assumed conversion of dilutive securities (2,275) 0 (5,646) 0
Net income (loss) attributable to common shareholders - diluted $ 2,094 $ 0 $ 2,184 $ 0
Weighted average shares outstanding (basic) (in shares) 23,000 1 12,924 1
Weighted average shares outstanding (diluted) (in shares) 63,456 1 38,758 1
Earnings (loss) per share (basic) (in dollars per share) $ 0.19 $ 0.00 $ 0.61 $ 0.00
Earnings (loss) per share (diluted) (in dollars per share) $ 0.03 $ 0.00 $ 0.06 $ 0.00
OP units [Member] | NSA OP, LP [Member]        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Effect of dilutive securities (in shares) 21,109 0 13,773 0
OP units [Member] | DownREIT Partnership [Member]        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Effect of dilutive securities (in shares) 1,432 0 949 0
LTIP units [Member] | NSA OP, LP [Member]        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Effect of dilutive securities (in shares) 1,844 0 1,030 0
Subordinated performance units [Member] | NSA OP, LP And DownREIT Partnership [Member]        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Effect of dilutive securities (in shares) 16,071 0 10,082 0