Annual report pursuant to Section 13 and 15(d)

ORGANIZATION AND NATURE OF OPERATIONS (Details)

v3.3.1.900
ORGANIZATION AND NATURE OF OPERATIONS (Details)
$ / shares in Units, storage_unit in Thousands, $ in Thousands, ft² in Millions
 3 Months Ended 9 Months Ended 10 Months Ended 12 Months Ended
May. 18, 2015
USD ($)
shares
Apr. 28, 2015
$ / shares
shares
Apr. 01, 2014
property
Jun. 10, 2013
property
Jun. 07, 2013
USD ($)
shares
Apr. 01, 2013
property
Feb. 13, 2013
Mar. 31, 2013
entity
property
Dec. 31, 2013
USD ($)
shares
Mar. 31, 2014
property
Dec. 31, 2015
USD ($)
ft²
storage_unit
state
property
$ / shares
shares
Dec. 31, 2014
USD ($)
$ / shares
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]                        
Common shares of beneficial interest, par value (in dollars per share) | $ / shares                     $ 0.01 $ 0.01
Net proceeds from issuance of common shares in IPO | $                 $ 0   $ 278,070 $ 0
Number of self storage properties owned | property                     277  
Number of states that self storage properties are owned in | state                     16  
Total rentable square feet in self storage properties | ft²                     15.8  
Number of storage units owned | storage_unit                     123  
National Storage Affiliates Holdings LLC [Member]                        
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]                        
Percentage of NSA owned by NSA Holdings prior to IPO             100.00%          
NSA Predecessor [Member]                        
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]                        
Legal entities under common control prior to formation of the Company | entity               2        
Number of self storage properties owned | property               110        
Number of properties contributed | property     65 23   88       88    
Number of properties not meeting criteria for contribution | property           22   22        
OP units [Member] | NSA OP, LP [Member]                        
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]                        
Amount of OP units issued in exchange for common shares from initial public offering (in shares) 23,000,000                      
OP units [Member] | National Storage Affiliates Holdings LLC [Member]                        
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]                        
OP units owned by NSA Holdings prior to IPO (in shares)         126,400              
Cash purchase price of OP Units held by NSA Holdings | $         $ 600              
Common Shares [Member]                        
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]                        
Shares offered during initial public offering (in shares)         1,000       1,000   23,000,000  
Common shares of beneficial interest, par value (in dollars per share) | $ / shares                     $ 0.01  
Net proceeds from issuance of common shares in IPO | $ $ 278,100                      
Common Shares [Member] | IPO [Member]                        
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]                        
Shares offered during initial public offering (in shares)   20,000,000                    
IPO share price (in dollars per share) | $ / shares   $ 13.00                    
Common Shares [Member] | Over-Allotment Option [Member]                        
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]                        
Shares offered during initial public offering (in shares) 3,000,000