Investments in Unconsolidated Real Estate Entities - Schedule of Equity in Earnings of Unconsolidated Real Estate Ventures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	$ 32,358	$ 22,361	$ 11,274
SmartStop Self Storage REIT, Inc. Preferred Stock
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	12,500	9,968	1,636
PRISA Self Storage LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	2,719	2,229	2,327
Storage Portfolio II JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	1,802	559	291
Storage Portfolio I LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	2,833	1,636	1,809
VRS Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	4,352	3,509	3,583
ESS-NYFL JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	427	(331)	(96)
WICNN JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	1,050	1,878	1,373
Extra Space Northern Properties Six LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	1,363	1,088	1,091
Alan Jathoo JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	270	57	(47)
ESS Bristol Investments LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	177	(67)	(262)
GFN JV, LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	546	788	450
PR EXR Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	491	(211)	(443)
Storage Portfolio IV JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	112	0	0
ESS-CA TIVS JV LP
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	1,274	0	0
PR II EXR JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	(8)	0	0
Other minority owned stores
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	$ 2,450	$ 1,258	$ (438)