v3.25.3

Fair Value Measurements - Schedule of Fair Value Measurements, Nonrecurring (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands | Sep. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loans individually evaluated for impairment measured at fair value | $ 72,151 | $ 50,449
Other real estate owned measured at fair value | 12,050 | 319
Level 1: Quoted Prices in Active Markets For Identical Assets |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loans individually evaluated for impairment measured at fair value | 0 | 0
Other real estate owned measured at fair value | 0 | 0
Level 2: Significant Other Observable Inputs |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loans individually evaluated for impairment measured at fair value | 0 | 0
Other real estate owned measured at fair value | 12,000 | 319
Level 3: Significant Unobservable Inputs |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loans individually evaluated for impairment measured at fair value | 72,151 | 50,449
Other real estate owned measured at fair value | $ 50 | $ 0

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- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This element represents the fair value of impaired loans as of the balance sheet date. + References No definition available. + Details
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Namespace Prefix: | fgbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This element represents the fair value of other real estate owned by bank. + References No definition available. + Details
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Namespace Prefix: | fgbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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