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, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	$ 41,428	$ 32,358	$ 22,361
Dividend income from SmartStop preferred stock
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	12,509	12,500	9,968
Equity in earnings of PRISA Self Storage LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	3,272	2,719	2,229
Equity in earnings of Storage Portfolio II JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	3,398	1,802	559
Equity in earnings of Storage Portfolio IV JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	917	112	0
Equity in earnings of Storage Portfolio I LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	4,684	2,833	1,636
Equity in earnings of PR II EXR JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	1,229	(8)	0
Equity in earnings of ESS-CA TIVS JV LP
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	2,753	1,274	0
Equity in earnings of VRS Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	5,401	4,352	3,509
Equity in earnings of ARA-EXR JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	180	0	0
Equity in earnings of ESS-NYFL JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	803	427	(331)
Equity in earnings of Extra Space Northern Properties Six LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	1,734	1,363	1,088
Equity in earnings of ESS-BGO Atlanta GA JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	55	0	0
Equity in earnings of Alan Jathoo JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	482	270	57
Equity in earnings of Bristol Investments LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	350	177	(67)
Equity in earnings of Storage Portfolio V JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	(33)	0	0
Equity in earnings of PR EXR Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	1,030	491	(211)
Equity in earnings of WICNN JV LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	0	1,050	1,878
Equity in earnings of GFN JV, LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	0	546	788
Other unconsolidated real estate ventures
Schedule of Equity Method Investments [Line Items]
Equity in earnings and dividend income from unconsolidated real estate entities	$ 2,664	$ 2,450	$ 1,258