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 |
12 Months Ended |
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2013 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
| Numerator |
|
|
|
|
|
|
|
|
|
|
|
|
| Net income (loss) |
$ 5,365
|
$ 2,109
|
$ 93
|
$ (2,771)
|
$ (2,371)
|
$ (5,025)
|
$ (6,158)
|
$ (2,803)
|
$ (10,481)
|
$ 4,796
|
$ (16,357)
|
|
| Net loss attributable to noncontrolling interests |
|
|
|
|
|
|
|
|
10,481
|
7,644
|
16,357
|
|
| Net income (loss) attributable to National Storage Affiliates Trust and NSA predecessor |
$ 4,604
|
$ 4,372
|
$ 3,464
|
$ 0
|
$ 0
|
$ 0
|
$ 0
|
$ 0
|
0
|
12,440
|
0
|
|
| Distributed and undistributed earnings allocated to participating securities |
|
|
|
|
|
|
|
|
0
|
(9)
|
0
|
|
| Net income (loss) attributable to common shareholders - basic |
|
|
|
|
|
|
|
|
0
|
12,431
|
0
|
|
| Effect of assumed conversion of dilutive securities |
|
|
|
|
|
|
|
|
0
|
(4,919)
|
0
|
|
| Net income (loss) attributable to common shareholders - diluted |
|
|
|
|
|
|
|
|
$ 0
|
$ 7,512
|
$ 0
|
|
| Denominator |
|
|
|
|
|
|
|
|
|
|
|
|
| Weighted average shares outstanding (basic) (in shares) |
|
|
|
|
|
|
|
|
1
|
15,463
|
1
|
|
| Weighted average shares outstanding (diluted) (in shares) |
|
|
|
|
|
|
|
|
1
|
45,409
|
1
|
|
| Earnings (loss) per share (basic) (in dollars per share) |
$ 0.20
|
$ 0.19
|
$ 0.22
|
$ 0.00
|
$ 0.00
|
$ 0.00
|
$ 0.00
|
$ 0.00
|
$ 0.00
|
$ 0.80
|
$ 0.00
|
|
| Earnings (loss) per share (diluted) (in dollars per share) |
$ 0.08
|
$ 0.03
|
$ 0.00
|
$ 0.00
|
$ 0.00
|
$ 0.00
|
$ 0.00
|
$ 0.00
|
$ 0.00
|
0.17
|
0.00
|
|
| Dividends declared per common share (in dollars per share) |
|
|
|
|
|
|
|
|
|
$ 0.54
|
$ 0.00
|
$ 0.00
|
| OP units [Member] |
|
|
|
|
|
|
|
|
|
|
|
|
| Denominator |
|
|
|
|
|
|
|
|
|
|
|
|
| Effect of dilutive securities (in shares) |
|
|
|
|
|
|
|
|
0
|
15,697
|
0
|
|
| DownREIT OP units [Member] |
|
|
|
|
|
|
|
|
|
|
|
|
| Denominator |
|
|
|
|
|
|
|
|
|
|
|
|
| Effect of dilutive securities (in shares) |
|
|
|
|
|
|
|
|
0
|
1,171
|
0
|
|
| LTIP units [Member] |
|
|
|
|
|
|
|
|
|
|
|
|
| Denominator |
|
|
|
|
|
|
|
|
|
|
|
|
| Effect of dilutive securities (in shares) |
|
|
|
|
|
|
|
|
0
|
1,272
|
0
|
|
| Class B And DownREIT Class B Units [Member] |
|
|
|
|
|
|
|
|
|
|
|
|
| Denominator |
|
|
|
|
|
|
|
|
|
|
|
|
| Effect of dilutive securities (in shares) |
|
|
|
|
|
|
|
|
0
|
11,806
|
0
|
|