Annual report pursuant to Section 13 and 15(d)

Investment in Storage Facilities - Additional Information (Detail)

v3.8.0.1
Investment in Storage Facilities - Additional Information (Detail)
12 Months Ended
Jul. 15, 2016
USD ($)
Facility
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Property
$ / shares
Dec. 31, 2016
USD ($)
Property
Store
$ / shares
Dec. 31, 2015
USD ($)
Property
Investment Holdings [Line Items]          
Number of storage facilities acquired | Property     2 122  
Stores acquired at certificate of occupancy | Store       3  
Cash paid for properties acquired     $ 22,626,000 $ 1,796,900,000  
Cash acquired during purchase       40,900,000  
Deposits paid at the time of contract         $ 5,300,000
Acquisition costs     0 29,542,000 2,991,000
Net other liabilities assumed     $ 12,000 7,200,000 1,300,000
Issuance of Operating Partnership Units       9,500,000 2,100,000
Fair value of three mortgages       11,300,000  
Settlement of a straight-line rent liability         2,500,000
Amortization period for in-place customer leases on a straight-line basis     12 months    
Amortization expense related to in-place customer leases     $ 24,800,000 29,900,000 3,400,000
Amortization expense expected for 2018     0    
Net proceeds from the sale of storage facilities     $ 18,872,000 34,697,000 $ 4,646,000
Sale leaseback transaction, lease terms     The Company has subsequently leased one of the properties sold during 2017 and will continue to operate the property through March 2020.    
Sale leaseback transaction, period till property continues to operate     2020-03    
Increase in depreciation expense due to signs     $ 500,000 $ 8,200,000  
Increase in depreciation expense due to facility replacement     $ 3,900,000    
Accelerated depreciation reduced basic and diluted earnings per share | $ / shares     $ 0.09 $ 0.19  
Scenario Forecast [Member]          
Investment Holdings [Line Items]          
Increase in depreciation expense due to facility replacement   $ 300,000      
Property Dispositions [Member]          
Investment Holdings [Line Items]          
Number of properties sold | Property     2 8 3
Net proceeds from the sale of storage facilities     $ 16,900,000 $ 34,100,000 $ 4,600,000
Number of properties sold, leased back | Property     1    
LifeStorage, LP [Member]          
Investment Holdings [Line Items]          
Number of self-storage facilities under contract to be purchased | Facility 83        
Payment for self-storage facilities under contract $ 1,300,000,000        
Discharge of indebtedness 482,000,000        
Prepayment penalties and defeasance costs $ 15,500,000        
2017 Acquisitions [Member]          
Investment Holdings [Line Items]          
Cash paid for properties acquired     $ 22,600,000    
Deposits paid at the time of contract       $ 600,000 500,000
2016 Acquisitions [Member]          
Investment Holdings [Line Items]          
Acquisition costs         $ 345,000