| Document And Entity Information | Mar. 31, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Mar. 31, 2022 |
| Entity Registrant Name | GLOBAL SELF STORAGE, INC. |
| Entity Central Index Key | 0001031235 |
| Entity Emerging Growth Company | false |
| Entity File Number | 001-12681 |
| Entity Incorporation, State or Country Code | MD |
| Entity Tax Identification Number | 13-3926714 |
| Entity Address, Address Line One | 3814 Route 44 |
| Entity Address, City or Town | Millbrook |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 12545 |
| City Area Code | (212) |
| Local Phone Number | 785-0900 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.01 par value |
| Trading Symbol | SELF |
| Security Exchange Name | NASDAQ |
