Noncontrolling Interest in Operating Partnership and Other Noncontrolling Interests - Schedule of OP Unit Activity (Details) - shares	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023
Noncontrolling Interest [Abstract]
OP Units redeemed for common stock (in shares)	264,145	0

Noncontrolling Interest, Operating Partnership Units Redeemed For Common Stock

No definition available.

Name:	exr_NoncontrollingInterestOperatingPartnershipUnitsRedeemedForCommonStock
Namespace Prefix:	exr_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration