XML 90 R80.htm IDEA: XBRL DOCUMENT
v3.23.3

Earning Per Share - Additional Information (Detail) - shares | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |  |
Incremental shares included in calculation of diluted EPS |  |  |  | 14,748,967
Stock Options |  |  |  |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |  |
Shares excluded from calculation of diluted earnings per share | 300,000 | 393,333 | 346,667 | 393,333
Restricted Stock Units Diluted |  |  |  |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |  |
Non-vested restricted stock, units and options |  |  |  | 107,005
Stock Options Diluted |  |  |  |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |  |
Non-vested restricted stock, units and options |  |  |  | 92,360

X
- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482662/260-10-50-1 + Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
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_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480454/718-10-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482662/260-10-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482689/260-10-45-22 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 23 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482689/260-10-45-23 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28A -Publisher FASB -URI https://asc.fasb.org//1943274/2147482689/260-10-45-28A + Details
Name: | us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482662/260-10-50-1 + Details
Name: | us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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