Organization	6 Months Ended
Jun. 30, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	1. ORGANIZATION Global Self Storage, Inc. (the “Company,” “we,” “our,” “us”) is a self-administered and self-managed Maryland real estate investment trust (“REIT”) that owns, operates, manages, acquires, develops and redevelops self storage properties (“stores” or “properties”) in the United States. As of June 30, 2021, through its wholly owned subsidiaries, the Company owned and/or managed 13 self-storage properties in Connecticut, Illinois, Indiana, New York, Ohio, Pennsylvania, South Carolina, and Oklahoma. The Company operates primarily in one segment: rental operations.

The entire disclosure for the nature of an entity's business, major products or services, principal markets including location, and the relative importance of its operations in each business and the basis for the determination, including but not limited to, assets, revenues, or earnings. For an entity that has not commenced principal operations, disclosures about the risks and uncertainties related to the activities in which the entity is currently engaged and an understanding of what those activities are being directed toward.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e5967-108592

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-URI http://asc.fasb.org/topic&trid=2134479

Name:	us-gaap_NatureOfOperations
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration