Schedule III - Additional Information (Details)	Dec. 31, 2023 USD ($)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Aggregate cost of real estate for U.S. federal income tax purposes	$ 62,766,523

Aggregate cost of real estate for U.S. Federal income tax purpose.

No definition available.

Name:	self_AggregateCostOfRealEstateForUSFederalIncomeTaxPurpose
Namespace Prefix:	self_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant