Annual report pursuant to Section 13 and 15(d)

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

v3.8.0.1
EARNINGS PER SHARE - Basic and Diluted Earnings per Share (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Numerator                      
Net income $ 12,015 $ 11,226 $ 15,576 $ 7,181 $ 6,075 $ 7,944 $ 6,045 $ 4,802 $ 45,998 $ 24,866 $ 4,796
Net (income) loss attributable to noncontrolling interests                 (43,037) (6,901) 7,644
Net income attributable to National Storage Affiliates Trust                 2,961 17,965 12,440
Distributions to preferred shareholders                 (2,300) 0 0
Distributed and undistributed earnings allocated to participating securities                 (28) (18) (9)
Net income attributable to common shareholders - basic                 633 17,947 12,431
Effect of assumed conversion of dilutive securities                 0 6,783 (4,919)
Net income attributable to common shareholders - diluted                 $ 633 $ 24,730 $ 7,512
Denominator                      
Weighted average shares outstanding - basic (in shares)                 44,423 29,887 15,463
Weighted average shares outstanding - diluted (in shares)                 44,423 78,747 45,409
Earnings (loss) per share - basic (in dollars per share) $ (0.08) $ 0.03 $ 0.05 $ 0.01 $ 0.22 $ 0.00 $ 0.32 $ 0.10 $ 0.01 $ 0.60 $ 0.80
Earnings (loss) per share - diluted (in dollars per share) $ (0.08) $ 0.03 $ 0.05 $ 0.01 $ 0.07 $ 0.00 $ 0.08 $ 0.07 0.01 0.31 0.17
Dividends declared per common share (in dollars per share)                 $ 1.04 $ 0.88 $ 0.54
OP units [Member] | NSA OP, LP [Member]                      
Denominator                      
Effect of dilutive securities (in shares)                 0 24,262 15,697
OP units [Member] | DownREIT Partnership [Member]                      
Denominator                      
Effect of dilutive securities (in shares)                 0 1,835 1,171
LTIP units [Member] | NSA OP, LP [Member]                      
Denominator                      
Effect of dilutive securities (in shares)                 0 1,846 1,272
Subordinated performance units [Member] | NSA OP, LP And DownREIT Partnership [Member]                      
Denominator                      
Effect of dilutive securities (in shares)                 0 20,917 11,806