XML 50 R36.htm IDEA: XBRL DOCUMENT
v3.22.1

Real Estate Assets - Additional Information (Details) | 12 Months Ended
--- | ---
Dec. 31, 2020 ft²
McCordsville, IN |
Real Estate Properties [Line Items] |
Gross square feet of traditional drive-up storage units and all-climate-controlled units | 13,713
Number of leasable unit | 7,300
Millbrook, NY |
Real Estate Properties [Line Items] |
Gross square feet of traditional drive-up storage units and all-climate-controlled units | 11,800

X
- Definition Leasable square feet. + References No definition available. + Details
Name: | self_LeasableSquareFeet
Namespace Prefix: | self_
Data Type: | dtr-types:areaItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of leasable units. + References No definition available. + Details
Name: | self_NumberOfLeasableUnits
Namespace Prefix: | self_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_RealEstatePropertiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_StatementGeographicalAxis=self_McCordsvilleIndianaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=self_MillbrookNYMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |