Fair Value Disclosures - Additional Information (Detail) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2024 USD ($) store	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) store	Jun. 30, 2023 USD ($)
Fair Value Disclosures [Abstract]
Number of operating stores held-for-sale \| store	7		7
Loss on real estate assets held for sale \| $	$ 54,659	$ 0	$ 54,659	$ 0

Gains losses on real estate transactions and earn out from prior acquisition and sales of other assets

No definition available.

Name:	exr_GainsLossesOnRealEstateTransactionsAndEarnOutFromPriorAcquisitionAndSaleOfOtherAssets
Namespace Prefix:	exr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration