Investments in Unconsolidated Real Estate Entities - Schedule of Investments in Unconsolidated Real Estate Ventures (Details) $ in Thousands					1 Months Ended		12 Months Ended
	Dec. 16, 2021 USD ($)	Mar. 01, 2021 USD ($) store	Dec. 18, 2020 USD ($)	Apr. 11, 2019 USD ($)	Jun. 30, 2021 USD ($) store	Oct. 31, 2019	Dec. 31, 2021 USD ($) property	Dec. 31, 2020 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of Stores | property							283
Equity Ownership %		55.00%
Investment balance							$ 393,744	$ 350,318
Number of stores sold | store		16
Gain (loss) on sale					$ 525
Exchange of real estate for interest in joint venture		$ 33,556
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Schedule of Equity Method Investments [Line Items]
Proceeds from sale of real estate assets	$ 200,292	$ 132,759	$ 46,592	$ 11,272
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							$ 59,393	60,092
WICNN JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property							0
Equity Ownership %							10.00%
Excess Profit %							35.00%
Investment balance							$ 0	36,032
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							$ (14,269)	17,186
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							$ 32,288	0
GFN JV, LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property							0
Equity Ownership %							10.00%
Excess Profit %							30.00%
Investment balance							$ 0	18,397
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							$ 11,796	12,211
PRISA Self Storage LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property							85
Equity Ownership %							4.00%
Excess Profit %							4.00%
Investment balance							$ 8,792	8,815
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							$ 7,621	7,780
Storage Portfolio IV JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property							27
Equity Ownership %							10.00%
Excess Profit %							30.00%
Investment balance							$ 40,174	0
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							$ 5,596	5,726
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							$ 2,628	2,810
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							$ (3,029)	(2,541)
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							$ (6,116)	(5,441)
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							$ (40,168)	(39,144)
PR II EXR JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores | property							18
Equity Ownership %							25.00%
Excess Profit %							25.00%
Investment balance							$ 70,403	0
Other minority owned stores
Schedule of Equity Method Investments [Line Items]
Number of Stores | property							13
Investment balance							$ 18,635	28,395
Other minority owned stores | Minimum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %							10.00%
Excess Profit %							19.00%
Other minority owned stores | 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
WICNN JV LLC And GFN JV, LLC
Schedule of Equity Method Investments [Line Items]
Number of stores sold | store					17
Gain (loss) on sale					$ 5,739