Annual report pursuant to Section 13 and 15(d)

Organization - Additional Information (Detail)

v3.10.0.1
Organization - Additional Information (Detail)
12 Months Ended
Dec. 31, 2018
Property
State
Organization [Line Items]  
Number of self-storage properties owned and managed 774
Number of states in which self-storage properties owned and managed | State 28
Number of properties managed under joint ventures 113
Number of properties managed with no ownership 100
Number of leased properties 4
Geographic Concentration Risk [Member] | Texas [Member] | Revenue [Member]  
Organization [Line Items]  
Concentration risk, percentage 21.00%
Geographic Concentration Risk [Member] | Florida [Member] | Revenue [Member]  
Organization [Line Items]  
Concentration risk, percentage 13.00%