ORGANIZATION AND NATURE OF OPERATIONS (Details) storage_unit in Thousands, ft² in Millions	3 Months Ended
	Mar. 31, 2024 ft² property storage_unit state 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	1,050
Number of states in which self storage properties are located | state	42
Total rentable square feet in self storage properties | ft²	68.7
Self storage properties	476
Self storage properties, remaining	333
Number of units in real estate property | storage_unit	542
Consolidated properties
Schedule of Equity Method Investments [Line Items]
Number of self storage properties	809
Number of states in which self storage properties are located | state	38
Total rentable square feet in self storage properties | ft²	51.9
Number of storage units | storage_unit	407
Unconsolidated properties | Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of self storage properties	241
Number of states in which self storage properties are located | state	24
Total rentable square feet in self storage properties | ft²	16.7
Number of units in real estate property | storage_unit	135
Unconsolidated properties | Joint Venture | 2018 Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of self storage properties	104
Number of states in which self storage properties are located | state	17
Total rentable square feet in self storage properties | ft²	7.8
Number of units in real estate property | storage_unit	64
Company's equity interest in unconsolidated real estate ventures (percent)	25.00%
Unconsolidated properties | Joint Venture | 2016 Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of self storage properties	81
Number of states in which self storage properties are located | state	13
Total rentable square feet in self storage properties | ft²	5.7
Number of units in real estate property | storage_unit	47
Company's equity interest in unconsolidated real estate ventures (percent)	25.00%