Name:	fgbi_ConstructionLandDevelopment
Namespace Prefix:	fgbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents amount of the loans secured by one to four family residential properties in the process of foreclosure on balance sheet date.

No definition available.

Name:	fgbi_LoansSecuredByOneToFourFamilyResidentialPropertiesInProcessOfForeclosure
Namespace Prefix:	fgbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Carrying amount of other real estate not covered by loss sharing agreements not separately disclosed, including Non-farm non-residential.

No definition available.

Name:	fgbi_NonFarmNonResidential
Namespace Prefix:	fgbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Refers to the carrying amount of other real estate not covered by loss sharing agreements not separately disclosed, including residential.

No definition available.

Name:	fgbi_ResidentialRealEstateOwnedAcquiredByForeclosure
Namespace Prefix:	fgbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Carrying amount as of the balance sheet date of other real estate and foreclosed assets. Other real estate may include real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. Foreclosed assets include all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(4))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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

- References

No definition available.