Investments in Unconsolidated Real Estate Entities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) property store	Dec. 31, 2022 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	323
Investment balance	$ 532,333	$ 515,060
Purchase price	$ 20,622
Number of joint venture stores purchased | store	5
PRISA Self Storage LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	84
Equity Ownership %	4.00%
Excess Profit %	4.00%
Investment balance	$ 8,564	8,596
Storage Portfolio II JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	36
Equity Ownership %	10.00%
Excess Profit %	30.00%
Investment balance	$ (7,487)	(7,200)
Storage Portfolio IV JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	32
Equity Ownership %	10.00%
Excess Profit %	30.00%
Investment balance	$ 48,861	49,139
Storage Portfolio I LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	24
Equity Ownership %	34.00%
Excess Profit %	49.00%
Investment balance	$ (41,619)	(41,372)
PR II EXR JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	23
Equity Ownership %	25.00%
Excess Profit %	25.00%
Investment balance	$ 109,651	110,172
ESS-CA TIVS JV LP
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	16
Equity Ownership %	55.00%
Excess Profit %	60.00%
Investment balance	$ 30,405	30,778
VRS Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	16
Equity Ownership %	45.00%
Excess Profit %	54.00%
Investment balance	$ (15,613)	(15,399)
ESS-NYFL JV LP
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	11
Equity Ownership %	16.00%
Excess Profit %	24.00%
Investment balance	$ 11,224	11,332
Extra Space Northern Properties Six LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	10
Equity Ownership %	10.00%
Excess Profit %	35.00%
Investment balance	$ (3,565)	(3,382)
Alan Jathoo JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	9
Equity Ownership %	10.00%
Excess Profit %	10.00%
Investment balance	$ 7,361	7,414
ESS Bristol Investments LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	8
Equity Ownership %	10.00%
Excess Profit %	30.00%
Investment balance	$ 2,062	2,110
ARA-EXR JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	12
Equity Ownership %	10.00%
Excess Profit %	30.00%
Investment balance	$ 19,062	19,137
ESS - BGO Atlanta GA JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	8
Equity Ownership %	20.00%
Excess Profit %	35.00%
Investment balance	$ 35,398	30,467
ESS - BGO Storage JV I LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	6
Equity Ownership %	20.00%
Excess Profit %	35.00%
Investment balance	$ 22,898	7,466
Storage Portfolio V JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	6
Equity Ownership %	10.00%
Excess Profit %	30.00%
Investment balance	$ 9,509	9,517
PR EXR Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	5
Equity Ownership %	25.00%
Excess Profit %	40.00%
Investment balance	$ 58,252	58,476
Storage Portfolio III JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	5
Equity Ownership %	10.00%
Excess Profit %	30.00%
Investment balance	$ 5,438	5,467
Other unconsolidated real estate ventures
Schedule of Equity Method Investments [Line Items]
Number of Stores | property	12
Investment balance	$ 31,932	32,342
Other unconsolidated real estate ventures | Minimum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %	20.00%
Excess Profit %	20.00%
Other unconsolidated real estate ventures | Maximum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %	50.00%
Excess Profit %	50.00%
SmartStop Self Storage REIT, Inc. Preferred Stock
Schedule of Equity Method Investments [Line Items]
Investment balance	$ 200,000	$ 200,000
Investment, preferred dividend rate	6.25%
Period after which preferred stock dividend is subject to increase	5 years
Investment redemption restriction period	5 years