SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES SUMMMARY OF SIGNIFICANT ACCOUNTING POLICIES\ (Details)
$ in Millions |
3 Months Ended |
9 Months Ended |
12 Months Ended |
|
Mar. 31, 2013
USD ($)
|
Dec. 31, 2013
USD ($)
|
Dec. 31, 2015
USD ($)
segment
|
Dec. 31, 2014
USD ($)
|
| Property, Plant and Equipment [Line Items] |
|
|
|
|
| Advertising costs |
|
$ 0.8
|
$ 2.4
|
$ 1.7
|
| Number of reportable segments | segment |
|
|
1
|
|
| NSA Predecessor [Member] |
|
|
|
|
| Property, Plant and Equipment [Line Items] |
|
|
|
|
| Advertising costs |
$ 0.2
|
|
|
|
| Building and Improvements [Member] | Minimum [Member] |
|
|
|
|
| Property, Plant and Equipment [Line Items] |
|
|
|
|
| Useful life |
|
|
7 years
|
|
| Building and Improvements [Member] | Maximum [Member] |
|
|
|
|
| Property, Plant and Equipment [Line Items] |
|
|
|
|
| Useful life |
|
|
40 years
|
|
| Furniture and Equipment [Member] | Minimum [Member] |
|
|
|
|
| Property, Plant and Equipment [Line Items] |
|
|
|
|
| Useful life |
|
|
3 years
|
|
| Furniture and Equipment [Member] | Maximum [Member] |
|
|
|
|
| Property, Plant and Equipment [Line Items] |
|
|
|
|
| Useful life |
|
|
10 years
|
|
| Leases, Acquired-in-Place [Member] |
|
|
|
|
| Property, Plant and Equipment [Line Items] |
|
|
|
|
| Customer in-place lease, useful life |
|
|
12 months
|
|
| Customer in-place lease amortization expense |
|
$ 2.6
|
$ 12.0
|
$ 8.3
|