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Real Estate Investments, Joint Ventures, Extension Period

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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Net rentable area for properties owned.

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The number of real estate properties owned as of the balance sheet date.

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The number of states the entity operates in as of the balance sheet date.

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The number of units in a real estate property owned as of the balance sheet date.

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The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

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The book value of investments in real estate joint ventures including direct and indirect investments.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Narrative (Details) storage_unit in Thousands, $ in Thousands, ft² in Millions			3 Months Ended
	Feb. 13, 2024 USD ($)	Dec. 15, 2023 USD ($) extension_period	Sep. 30, 2024 USD ($) ft² storage_unit state property State	Dec. 31, 2023 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of self storage properties \| property			1,070
Number of states in which self storage properties are located \| state			42
Rentable square feet in self storage properties \| ft²			70.0
Investment in unconsolidated real estate ventures			$ 257,381	$ 211,361
Number of units in real estate property \| storage_unit			550
2024 Joint Venture
Schedule of Equity Method Investments [Line Items]
Real estate investments, joint ventures	$ 210,000
Company's equity interest in unconsolidated real estate ventures (percent)	6.05%
Real estate investments, joint ventures, maturity period	5 years
2023 Joint Venture
Schedule of Equity Method Investments [Line Items]
Real estate investments, joint ventures			$ 37,000
Real estate investments, joint ventures, maturity period		24 months
Real estate investments, joint ventures, number of extension periods \| extension_period		2
Real estate investments, joint ventures, extension period		6 months
Payments to acquire joint venture			$ 147,900
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%
Joint venture \| 2024 Joint Venture
Schedule of Equity Method Investments [Line Items]
Real estate investments, joint ventures	$ 140,800
2024 NSA Member \| 2024 Joint Venture
Schedule of Equity Method Investments [Line Items]
Real estate investments, joint ventures	$ 35,200
Company's equity interest in unconsolidated real estate ventures (percent)	25.00%
2024 JV Investor \| 2024 Joint Venture
Schedule of Equity Method Investments [Line Items]
Real estate investments, joint ventures	$ 105,600
Company's equity interest in unconsolidated real estate ventures (percent)	75.00%
Number of self storage properties \| property			56
Number of states in which self storage properties are located \| State			7
Rentable square feet in self storage properties \| ft²			3.2
Number of storage units \| storage_unit			24
2023 JV Members \| 2023 Joint Venture
Schedule of Equity Method Investments [Line Items]
Company's equity interest in unconsolidated real estate ventures (percent)		75.00%
Investment in unconsolidated real estate ventures		$ 400,000
2023 NSA Member \| 2023 Joint Venture
Schedule of Equity Method Investments [Line Items]
Company's equity interest in unconsolidated real estate ventures (percent)		25.00%
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
Rentable square feet in self storage properties \| ft²			18.0
Number of units in real estate property \| storage_unit			143
Unconsolidated properties \| Joint venture \| 2023 Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of self storage properties \| property			18
Number of states in which self storage properties are located \| state			2
Rentable square feet in self storage properties \| ft²			1.2
Number of units in real estate property \| storage_unit			8
Unconsolidated properties \| Joint venture \| 2018 Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of self storage properties \| property			104
Number of states in which self storage properties are located \| state			17
Rentable square feet in self storage properties \| ft²			7.9
Number of units in real estate property \| storage_unit			65
Unconsolidated properties \| Joint venture \| 2016 Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of self storage properties \| property			81
Number of states in which self storage properties are located \| state			13
Rentable square feet in self storage properties \| ft²			5.7
Number of units in real estate property \| storage_unit			47