Noncontrolling Interest in Operating Partnership and Other Noncontrolling Interests - Schedule of OP Unit Activity (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Jul. 20, 2023
Noncontrolling Interest [Abstract]
OP Units redeemed for common stock (in shares)	308,024	0
OP Units issued in conjunction with business combination acquisitions (in units)		1,674,748	0
Value of OP Units issued in conjunction with business combination and acquisitions		$ 249,470	$ 0

Noncontrolling Interest, Operating Partnership Units Issued With Acquisition, Value

No definition available.

Name:	exr_NoncontrollingInterestOperatingPartnershipUnitsIssuedWithAcquisitionValue
Namespace Prefix:	exr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant