ORGANIZATION AND NATURE OF OPERATIONS (Details) storage_unit in Thousands, ft² in Millions	9 Months Ended
	Sep. 30, 2024 ft² state storage_unit property 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	1,070
Number of states in which self storage properties are located | state	42
Total rentable square feet in self storage properties | ft²	70.0
Number of units in real estate property | storage_unit	550
2018 Joint Venture
Schedule of Equity Method Investments [Line Items]
Company's equity interest in unconsolidated real estate ventures (percent)	25.00%
2016 Joint Venture
Schedule of Equity Method Investments [Line Items]
Company's equity interest in unconsolidated real estate ventures (percent)	25.00%
Consolidated properties
Schedule of Equity Method Investments [Line Items]
Number of self storage properties | property	811
Number of states in which self storage properties are located | state	38
Total rentable square feet in self storage properties | ft²	52.0
Number of storage units | storage_unit	407
Unconsolidated properties | Joint venture
Schedule of Equity Method Investments [Line Items]
Number of self storage properties | property	259
Number of states in which self storage properties are located | state	24
Total rentable square feet in self storage properties | ft²	18.0
Number of units in real estate property | storage_unit	143