XML 51 R83.htm IDEA: XBRL DOCUMENT v3.2.0.727

Reconciliation of Weighted Average Shares for Basic and Diluted Earnings Per Share (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]
Weighted average shares for basic earnings per share	25,454,579	25,128,280	25,447,398	25,121,171
Weighted average shares for diluted earnings per share	25,680,997	25,312,938	25,659,869	25,301,783
Restricted Stock
Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]
Non-vested restricted stock and options	122,141	77,880	109,308	77,125
Stock Options
Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]
Non-vested restricted stock and options	104,277	106,778	103,163	103,487

X

- Definition

Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]

+ References

No definition available.

+ Details

Name:	gbli_ReconciliationOfBasicWeightedAverageSharesToDilutedWeightedAverageSharesLineItems
Namespace Prefix:	gbli_
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/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 260



-SubTopic 10



-Section 50



-Paragraph 1



-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257



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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 260



-SubTopic 10



-Section 45



-Paragraph 28A



-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1500-109256

+ Details

Name:	us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 260



-SubTopic 10



-Section 45



-Paragraph 16



-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1505-109256



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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 260



-SubTopic 10



-Section 50



-Paragraph 1



-Subparagraph (a)



-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

+ Details

Name:	us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 260



-SubTopic 10



-Section 50



-Paragraph 1



-Subparagraph (a)



-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257



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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 260



-SubTopic 10



-Section 45



-Paragraph 10



-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1448-109256



Reference 3: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Glossary Weighted-Average Number of Common Shares Outstanding



-URI http://asc.fasb.org/extlink&oid=6528421

+ Details

Name:	us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: