XML 64 R54.htm IDEA: XBRL DOCUMENT
v3.25.1

Subsequent Events - Additional Information (Details) - $ / shares |  |  | 12 Months Ended
--- | --- | --- | ---
Mar. 25, 2025 | Mar. 03, 2025 | Dec. 31, 2024 | Dec. 31, 2023
Subsequent Event | O 2024 A Dividends [Member] |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Cash dividend declared |  | $ 0.0725 |  |
Dividend declared date |  | Mar. 03, 2025 |  |
Dividend payable date |  | Mar. 31, 2025 |  |
Dividend record date |  | Mar. 17, 2025 |  |
Restricted Stock Awards | Subsequent Event |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Number of shares, granted | 40,726 |  |  |
Performance-Based Restricted Stock Grants |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Number of shares, granted |  |  | 47,452 | 30,217
Performance-Based Restricted Stock Grants | Subsequent Event |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Number of shares, granted | 23,726 |  |  |
2017 Equity Incentive Plan | Subsequent Event |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Remaining vesting period | 4 years |  |  |
2017 Equity Incentive Plan | Subsequent Event | Minimum |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Stock vested percentage based on achievement of goal | 0.00% |  |  |
2017 Equity Incentive Plan | Subsequent Event | Maximum |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Stock vested percentage based on achievement of goal | 200.00% |  |  |
2017 Equity Incentive Plan | Performance-Based Restricted Stock Grants |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Remaining vesting period |  |  | 4 years |
2017 Equity Incentive Plan | Performance-Based Restricted Stock Grants | Minimum |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Stock vested percentage based on achievement of goal |  |  | 0.00% |
2017 Equity Incentive Plan | Performance-Based Restricted Stock Grants | Maximum |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Stock vested percentage based on achievement of goal |  |  | 200.00% |

X
- Definition Sharebased compensation arrangement by sharebased payment award award vesting rights percentage based on achievement of goal. + References No definition available. + Details
Name: | self_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageBasedOnAchievementOfGoal
Namespace Prefix: | self_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate dividends declared during the period for each share of common stock outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the declared dividend will be paid, in YYYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-3 + Details
Name: | us-gaap_DividendPayableDateToBePaidDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the dividend to be paid was declared, in YYYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-3 + Details
Name: | us-gaap_DividendsPayableDateDeclaredDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the holder must own the stock to be entitled to the dividend, in YYYY-MM-DD format. + References No definition available. + Details
Name: | us-gaap_DividendsPayableDateOfRecordDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(01) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481674/830-30-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 855 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483399/855-10-50-2 + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=self_O2024ADividendsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=self_PerformanceBasedRestrictedStockGrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=self_TwoThousandSeventeenEquityIncentivePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |