Quarterly report pursuant to Section 13 or 15(d)

Investment in Joint Ventures - Summary of Company's Unconsolidated Joint Ventures (Detail)

v3.19.1
Investment in Joint Ventures - Summary of Company's Unconsolidated Joint Ventures (Detail)
$ in Millions
Mar. 31, 2019
USD ($)
Property
Dec. 31, 2018
USD ($)
Sovran HHF Storage Holdings LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 57  
Company common ownership interest 20.00%  
Carrying value of investment $ 84.9 $ 85.8
Sovran HHF Storage Holdings II LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 30  
Company common ownership interest 15.00%  
Carrying value of investment $ 13.4 13.4
191 III Life Storage Holdings LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 6  
Company common ownership interest 20.00%  
Carrying value of investment $ 9.3 9.3
Life Storage-SERS Storage LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 3  
Company common ownership interest 20.00%  
Carrying value of investment $ 3.4 3.5
Life Storage-HIERS Storage LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 12  
Company common ownership interest 20.00%  
Carrying value of investment $ 9.3 9.3
Iskalo Office Holdings, LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Company common ownership interest 49.00%  
Carrying value of investment $ (0.4) (0.4)
Urban Box Coralway Storage, LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 1  
Company common ownership interest 85.00%  
Carrying value of investment $ 4.3 4.4
SNL/Orix 1200 McDonald Ave., LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 1  
Company common ownership interest 5.00%  
Carrying value of investment $ 2.8 2.8
SNL Orix Merrick, LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 1  
Company common ownership interest 5.00%  
Carrying value of investment $ 2.5 2.5
N 32nd Street Self Storage, LLC [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 1  
Company common ownership interest 46.00%  
Carrying value of investment $ 1.2 1.2
NYX Don Mills Storage LP [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 1  
Company common ownership interest 17.00%  
Carrying value of investment $ 1.0 1.0
NYX Sheridan Storage LP [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 1  
Company common ownership interest 38.30%  
Carrying value of investment $ 0.7 0.7
NYX Appleby Storage LP [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 1  
Company common ownership interest 37.50%  
Carrying value of investment $ 1.0 $ 1.0
Bluebird Sanford Storage LP [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 1  
Company common ownership interest 20.50%  
Carrying value of investment $ 0.3  
Bluebird Ingram Storage LP [Member]    
Schedule of Equity Method Investments [Line Items]    
Number of Properties | Property 1  
Company common ownership interest 46.30%  
Carrying value of investment $ 1.3