Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.2
Investment in Joint Ventures - Summary of Company's Unconsolidated Joint Ventures (Parenthetical) (Detail)
$ in Thousands
 1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Mar. 31, 2020
USD ($)
Property
Nov. 30, 2019
USD ($)
Property
Mar. 31, 2020
USD ($)
Property
Jun. 30, 2020
USD ($)
Property
Jun. 30, 2019
USD ($)
Dec. 31, 2019
USD ($)
Property
Schedule of Equity Method Investments [Line Items]            
Number of storage facilities acquired | Property     6 6    
Distributions from unconsolidated joint ventures       $ 6,086 $ 4,865  
Payment for property acquisition       124,204 95,819  
Mortgages payable       $ 34,519   $ 34,851
Ontario, Canada [Member]            
Schedule of Equity Method Investments [Line Items]            
Number of joint venture developing self-storage facilities | Property       2    
New York City [Member]            
Schedule of Equity Method Investments [Line Items]            
Number of joint venture developing self-storage facilities | Property       3    
Sovran HHF Storage Holdings LLC [Member]            
Schedule of Equity Method Investments [Line Items]            
Excess of investment over net asset due to capitalization of acquisition related costs       $ 1,700    
191 III Life Storage Holdings LLC [Member]            
Schedule of Equity Method Investments [Line Items]            
Payment for property acquisition $ 124,200          
Distributions from unconsolidated joint ventures $ 8,400          
191 III Life Storage Holdings LLC [Member] | Storage Facilities [Member] | California [Member]            
Schedule of Equity Method Investments [Line Items]            
Number of storage facilities acquired | Property 6          
Life Storage-HIERS Storage LLC [Member]            
Schedule of Equity Method Investments [Line Items]            
Contribution of company to joint venture as share in capital           $ 5,700
Life Storage-HIERS Storage LLC [Member] | Storage Facilities [Member]            
Schedule of Equity Method Investments [Line Items]            
Number of storage facilities acquired | Property   5       5
Payment for property acquisition   $ 56,300        
Mortgages payable   $ 27,600        
Iskalo Office Holdings, LLC [Member]            
Schedule of Equity Method Investments [Line Items]            
Rent paid during the period       600 $ 600  
Bluebird Sanford Storage LP [Member]            
Schedule of Equity Method Investments [Line Items]            
Contribution of company to joint venture as share in capital           $ 300
Bluebird Sanford Storage LP [Member] | Storage Facilities [Member]            
Schedule of Equity Method Investments [Line Items]            
Payment for property acquisition           4,900
Mortgages payable           3,200
Bluebird Ingram Storage LP [Member]            
Schedule of Equity Method Investments [Line Items]            
Contribution of company to joint venture as share in capital           1,300
Bluebird Ingram Storage LP [Member] | Storage Facilities [Member]            
Schedule of Equity Method Investments [Line Items]            
Payment for property acquisition           20,700
Mortgages payable           17,600
Life Storage Spacemax, LLC [Member]            
Schedule of Equity Method Investments [Line Items]            
Contribution of company to joint venture as share in capital           16,300
Life Storage Spacemax, LLC [Member] | Storage Facilities [Member]            
Schedule of Equity Method Investments [Line Items]            
Payment for property acquisition           82,700
Mortgages payable           $ 42,000
Number of self-storage facilities | Property           6
Life Storage Virtus, LLC [Member]            
Schedule of Equity Method Investments [Line Items]            
Contribution of company to joint venture as share in capital       $ 1,700    
Life Storage Virtus, LLC [Member] | Storage Facilities [Member]            
Schedule of Equity Method Investments [Line Items]            
Payment for property acquisition     $ 21,700      
Mortgages payable $ 14,000   $ 14,000      
Joint Ventures with Properties in Development Stage [Member]            
Schedule of Equity Method Investments [Line Items]            
Number Of joint ventures | Property       5    
Joint Ventures with Properties in Development Stage [Member] | Common Stock Shares [Member]            
Schedule of Equity Method Investments [Line Items]            
Contribution of company to joint venture as share in capital       $ 2,900