Quarterly report pursuant to Section 13 or 15(d)

ORGANIZATION AND NATURE OF OPERATIONS (Details)

v3.20.1
ORGANIZATION AND NATURE OF OPERATIONS (Details)
storage_unit in Thousands, ft² in Millions
3 Months Ended
Mar. 31, 2020
ft²
property
state
storage_unit
metropolitan_statistical_area
Schedule of Equity Method Investments [Line Items]  
Number of top metropolitan statistical areas for focus of operations | metropolitan_statistical_area 100
Number of self storage properties | property 780
Number of states in which self storage properties are located | state 35
Total rentable square feet in self storage properties | ft² 48.9
Number of storage units | storage_unit 392
Consolidated properties  
Schedule of Equity Method Investments [Line Items]  
Number of self storage properties | property 603
Number of states in which self storage properties are located | state 29
Total rentable square feet in self storage properties | ft² 36.2
Number of storage units | storage_unit 288
Unconsolidated real estate ventures | Joint Venture  
Schedule of Equity Method Investments [Line Items]  
Number of self storage properties | property 177
Number of states in which self storage properties are located | state 21
Total rentable square feet in self storage properties | ft² 12.7
Number of storage units | storage_unit 104
Company's equity interest in unconsolidated real estate ventures (percent) 25.00%