Name:	gbli_ManagementFeePayableRelatedParties
Namespace Prefix:	gbli_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Management Fees Related Parties

+ References

No definition available.

+ Details

Name:	gbli_ManagementFeesRelatedParties
Namespace Prefix:	gbli_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Minimum Voting Power To Nominate Directors

+ References

No definition available.

+ Details

Name:	gbli_MinimumVotingPowerToNominateDirectors
Namespace Prefix:	gbli_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Ordinary A Shares Issued

+ References

No definition available.

+ Details

Name:	gbli_OrdinaryASharesIssued
Namespace Prefix:	gbli_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Unfunded Capital Commitment

+ References

No definition available.

+ Details

Name:	gbli_UnfundedCapitalCommitment
Namespace Prefix:	gbli_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of direct costs of the business combination including legal, accounting, and other costs incurred to consummate the business acquisition.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.3)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

Name:	us-gaap_LegalFees
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of capital contributed by the limited partners.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 5

-Subparagraph (SAB TOPIC 4.F)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

+ Details

Name:	us-gaap_LimitedPartnersContributedCapital
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of cash paid for brokerage fees during the current period. This element is intended to represent the brokerage fees paid by and between financial industry participants.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3536-108585

+ Details

Name:	us-gaap_PaymentsForBrokerageFees
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Cash inflow received as distributions, returns of capital, or sale proceeds from partnership interests held for investment purposes.

+ References

No definition available.

+ Details

Name:	us-gaap_ProceedsFromLimitedPartnershipInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=gbli_FoxPaineAndCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=gbli_GlobalIndemnityGroupIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=gbli_AmericanReliableInsuranceCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=gbli_FoxPaineCapitalFundIiLimitedPartnerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=gbli_GlobalIndemnityReinsuranceCompanyLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=gbli_CozenOConnorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=gbli_CrystalAndCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Party Transactions - Additional Information (Detail) - USD ($)		3 Months Ended		6 Months Ended
	Jan. 01, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Related Party Transaction [Line Items]
Distribution received from the limited partnership				$ 4,287,000
Fox Paine & Company, LLC
Related Party Transaction [Line Items]
Company's total outstanding voting power		93.00%		93.00%
Minimum voting power required to nominate Directors		25.00%		25.00%
Management fees		$ 500,000	$ 500,000	$ 1,000,000	$ 1,000,000
Unpaid management fees		1,600,000		1,600,000		$ 600,000
Fox Paine & Company, LLC \| Global Indemnity Group Inc \| American Reliable Insurance Company
Related Party Transaction [Line Items]
Investment bank fee as a percentage of the amount paid plus required capital to operate American Reliable on a standalone basis	3.00%
Investment advisory fee	$ 1,500,000
Investment advisory fee	$ 6,500,000
Ordinary shares of Global Indemnity issued to pay fees	267,702
Fox Paine Capital Fund II Limited Partner \| Global Indemnity Reinsurance
Related Party Transaction [Line Items]
Company's investment in limited partnership		3,300,000		3,300,000		$ 3,400,000
Unfunded capital commitment		2,400,000		2,400,000
Distribution received from the limited partnership		0	0	800,000	0
Cozen O'Connor
Related Party Transaction [Line Items]
Cost incurred for legal services rendered		200,000	60,000	300,000	90,000
Crystal & Company
Related Party Transaction [Line Items]
Brokerage fee incurred		$ 60,000	$ 60,000	$ 100,000	$ 100,000