Noncontrolling Interest in Operating Partnership and Other Noncontrolling Interests - Schedule of OP Unit Activity (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021
Noncontrolling Interest [Abstract]
OP Units redeemed for cash (in shares)	0	13,028
Cash paid for OP Units redeemed	$ 0	$ 2,672

Noncontrolling Interest, Operating Partnership Units Redeemed, Cash Paid

No definition available.

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