$FGBI
First Guaranty Bancshares, Inc. Stock $fgbi

$fgbi Overview Financials Valuation SEC Filings Company Website

2020 Form 10-K Financial Statement

#000140853421000014 Filed on March 16, 2021

Income Statement

Concept	2020	2019 Q4	2019
Revenue	$100.7M		$91.64M
YoY Change	9.87%		16.91%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$2.800M	$840.0K	$2.300M
YoY Change	21.74%	-15.15%	9.52%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$26.02M		$29.97M
YoY Change	-13.18%		40.25%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$25.54M	$5.050M	$17.90M
YoY Change	42.69%	57.32%	1.26%
Income Tax	$5.219M	$1.000M	$3.656M
% Of Pretax Income	20.44%	19.8%	20.43%
Net Earnings	$20.32M	$4.050M	$14.24M
YoY Change	42.67%	54.58%	0.2%
Net Earnings / Revenue	20.18%		15.54%
Basic Earnings Per Share	$1.90		$1.34
Diluted Earnings Per Share	$2.093M	$416.7K	$1.464M
COMMON SHARES
Basic Shares Outstanding	10.72M shares	8.856M shares	10.67M shares
Diluted Shares Outstanding

Balance Sheet

Concept	2020	2019 Q4	2019
SHORT-TERM ASSETS
Cash & Short-Term Investments		$493.9M
YoY Change		-7.37%
Cash & Equivalents		$67.43M
Short-Term Investments		$426.5M
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$59.90M	$56.46M	$56.50M
YoY Change	6.02%	42.24%	42.32%
Goodwill		$12.90M
YoY Change		271.54%
Intangibles		$7.166M
YoY Change		103.12%
Long-Term Investments
YoY Change
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$2.473B	$2.117B	$2.117B
YoY Change	16.81%	16.51%	16.51%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$5.300M	$6.000M	$6.000M
YoY Change	-11.67%	50.0%	50.0%
Deferred Revenue
YoY Change
Short-Term Debt	$6.100M	$19.92M	$6.800M
YoY Change	-10.29%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$5.300M	$6.000M	$6.000M
YoY Change	-11.67%	50.0%	50.0%
LONG-TERM LIABILITIES
Long-Term Debt	$57.10M	$63.30M	$63.30M
YoY Change	-9.79%	83.48%	83.48%
Other Long-Term Liabilities	$6.200M	$5.400M	$5.400M
YoY Change	14.81%	200.0%	200.0%
Total Long-Term Liabilities	$63.30M	$68.70M	$68.70M
YoY Change	-7.86%	89.26%	89.26%
TOTAL LIABILITIES
Total Short-Term Liabilities	$5.300M	$6.000M	$6.000M
Total Long-Term Liabilities	$63.30M	$68.70M	$68.70M
Total Liabilities	$2.295B	$1.951B	$1.951B
YoY Change	17.59%	16.84%	16.85%
SHAREHOLDERS EQUITY
Retained Earnings		$43.28M
YoY Change		23.85%
Common Stock		$120.6M
YoY Change		0.92%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$178.6M	$166.0M	$166.0M
YoY Change
Total Liabilities & Shareholders Equity	$2.473B	$2.117B	$2.117B
YoY Change	16.81%	16.51%	16.51%

Cashflow Statement

Concept	2020	2019 Q4	2019
OPERATING ACTIVITIES
Net Income	$20.32M	$4.050M	$14.24M
YoY Change	42.67%	54.58%	0.2%
Depreciation, Depletion And Amortization	$2.800M	$840.0K	$2.300M
YoY Change	21.74%	-15.15%	9.52%
Cash From Operating Activities	$23.76M	$7.730M	$29.08M
YoY Change	-18.29%	22.31%	8.14%
INVESTING ACTIVITIES
Capital Expenditures	$6.313M	-$3.980M	$11.93M
YoY Change	-47.1%	197.01%	215.1%
Acquisitions
YoY Change
Other Investing Activities	-$122.1M	-$193.2M	-$120.0M
YoY Change	1.81%	-193310.0%	-1233.93%
Cash From Investing Activities	-$128.5M	-$197.2M	-$131.9M
YoY Change	-2.62%	15804.03%	-2042.94%
FINANCING ACTIVITIES
Cash Dividend Paid	$6.234M		$5.803M
YoY Change	7.43%		2.96%
Common Stock Issuance & Retirement, Net	$0.00		$1.000M
YoY Change	-100.0%
Debt Paid & Issued, Net	$6.302M		$3.754M
YoY Change	67.87%		27.64%
Cash From Financing Activities	$336.9M	77.93M	$42.29M
YoY Change	696.62%	32.0%	-24.83%
NET CHANGE
Cash From Operating Activities	$23.76M	7.730M	$29.08M
Cash From Investing Activities	-$128.5M	-197.2M	-$131.9M
Cash From Financing Activities	$336.9M	77.93M	$42.29M
Net Change In Cash	$232.2M	-111.5M	-$60.54M
YoY Change	-483.52%	-273.97%	-167.31%
FREE CASH FLOW
Cash From Operating Activities	$23.76M	$7.730M	$29.08M
Capital Expenditures	$6.313M	-$3.980M	$11.93M
Free Cash Flow	$17.45M	$11.71M	$17.15M
YoY Change	1.76%	52.87%	-25.79%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2020	dei	Entity Central Index Key EntityCentralIndexKey	0001408534
CY2020	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
CY2020	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2020	dei	Amendment Flag AmendmentFlag	false
CY2020	dei	Document Type DocumentType	10-K
CY2020	dei	Document Annual Report DocumentAnnualReport	true
CY2020	dei	Document Period End Date DocumentPeriodEndDate	2020-12-31
CY2020	dei	Local Phone Number LocalPhoneNumber	345-7685
CY2020	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2020	dei	Document Transition Report DocumentTransitionReport	false
CY2020	dei	Entity File Number EntityFileNumber	001-37621
CY2020	dei	Entity Registrant Name EntityRegistrantName	FIRST GUARANTY BANCSHARES, INC.
CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	LA
CY2020	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	26-0513559
CY2020	dei	Entity Address Address Line1 EntityAddressAddressLine1	400 East Thomas Street
CY2020	dei	Entity Address City Or Town EntityAddressCityOrTown	Hammond,
CY2020	dei	Entity Address State Or Province EntityAddressStateOrProvince	LA
CY2020	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	70401
CY2020	dei	City Area Code CityAreaCode	(985)
CY2020	dei	Security12b Title Security12bTitle	Common Stock, $1 par value
CY2020	dei	Trading Symbol TradingSymbol	FGBI
CY2020	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2020	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	No
CY2020	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
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CY2020	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2020	dei	Entity Filer Category EntityFilerCategory	Accelerated Filer
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CY2018	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.58
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	9741253	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	9695131	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	9687123	shares
CY2020	us-gaap	Net Income Loss NetIncomeLoss	20318000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	14241000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	14213000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	12757000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	11435000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-8508000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	14791000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-353000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-1830000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Writedown Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesBeforeTax	100000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Writedown Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesBeforeTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Writedown Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesBeforeTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentBeforeTaxPortionAttributableToParent	-1934000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentBeforeTaxPortionAttributableToParent	11788000	USD
CY2018	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentBeforeTaxPortionAttributableToParent	-6678000	USD
CY2020	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	-406000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	2475000	USD
CY2018	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	-1402000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-1528000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	9313000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-5276000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	18790000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	23554000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	8937000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	143983000	USD
CY2018	us-gaap	Tax Cuts And Jobs Act Of2017 Reclassification From Aoci To Retained Earnings Tax Effect TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect	0	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	14213000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-5276000	USD
CY2018	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.58
CY2018	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	5636000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	147284000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	14241000	USD
CY2019	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	54130	shares
CY2019	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	1000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	9313000	USD
CY2019	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.60
CY2019	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	5803000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	166035000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	20318000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-1528000	USD
CY2020	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.64
CY2020	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	6234000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	178591000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	20318000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	14241000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	14213000	USD
CY2020	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	14877000	USD
CY2019	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	4860000	USD
CY2018	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	1354000	USD
CY2020	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	3781000	USD
CY2019	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	3057000	USD
CY2018	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	3289000	USD
CY2020	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-2594000	USD
CY2019	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-1347000	USD
CY2018	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-1445000	USD
CY2020	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	14791000	USD
CY2019	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	-157000	USD
CY2018	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	-1830000	USD
CY2020	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net Heldtomaturity Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetHeldtomaturitySecurities	100000	USD
CY2019	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net Heldtomaturity Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetHeldtomaturitySecurities	0	USD
CY2018	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net Heldtomaturity Securities OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetHeldtomaturitySecurities	0	USD
CY2020	us-gaap	Gains Losses On Sales Of Assets GainsLossesOnSalesOfAssets	1054000	USD
CY2019	us-gaap	Gains Losses On Sales Of Assets GainsLossesOnSalesOfAssets	1304000	USD
CY2018	us-gaap	Gains Losses On Sales Of Assets GainsLossesOnSalesOfAssets	301000	USD
CY2020	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-1245000	USD
CY2019	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-90000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	29078000	USD
CY2018	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	47000	USD
CY2020	fgbi	Fhlb Stock Dividends FhlbStockDividends	43000	USD
CY2019	fgbi	Fhlb Stock Dividends FhlbStockDividends	63000	USD
CY2018	fgbi	Fhlb Stock Dividends FhlbStockDividends	42000	USD
CY2020	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	0	USD
CY2019	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	-344000	USD
CY2018	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	-964000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	3268000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-6349000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-4184000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	23759000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	26889000	USD
CY2020	us-gaap	Proceeds From Sale And Maturity Of Held To Maturity Securities ProceedsFromSaleAndMaturityOfHeldToMaturitySecurities	34022000	USD
CY2019	us-gaap	Proceeds From Sale And Maturity Of Held To Maturity Securities ProceedsFromSaleAndMaturityOfHeldToMaturitySecurities	21190000	USD
CY2018	us-gaap	Proceeds From Sale And Maturity Of Held To Maturity Securities ProceedsFromSaleAndMaturityOfHeldToMaturitySecurities	11197000	USD
CY2020	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	1242559000	USD
CY2019	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	279590000	USD
CY2018	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	384549000	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1078450000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	274437000	USD
CY2018	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	309346000	USD
CY2020	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	322745000	USD
CY2019	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	123553000	USD
CY2018	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	76354000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	6313000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	11933000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	3787000	USD
CY2020	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	127000	USD
CY2019	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	12000	USD
CY2018	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	46000	USD
CY2020	us-gaap	Proceeds From Sale Of Other Real Estate ProceedsFromSaleOfOtherRealEstate	2345000	USD
CY2019	us-gaap	Proceeds From Sale Of Other Real Estate ProceedsFromSaleOfOtherRealEstate	550000	USD
CY2018	us-gaap	Proceeds From Sale Of Other Real Estate ProceedsFromSaleOfOtherRealEstate	484000	USD
CY2020	fgbi	Cash Paid In Excess Of Cash Received In Acquisition CashPaidInExcessOfCashReceivedInAcquisition	0	USD
CY2019	fgbi	Cash Paid In Excess Of Cash Received In Acquisition CashPaidInExcessOfCashReceivedInAcquisition	23325000	USD
CY2018	fgbi	Cash Paid In Excess Of Cash Received In Acquisition CashPaidInExcessOfCashReceivedInAcquisition	0	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-128455000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-131906000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	6789000	USD
CY2020	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	313210000	USD
CY2019	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	18408000	USD
CY2018	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	80336000	USD
CY2020	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	36202000	USD
CY2019	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-28000	USD
CY2018	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-15500000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	0	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	32465000	USD
CY2018	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	0	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	6302000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	3754000	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	2941000	USD
CY2020	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	1000000	USD
CY2018	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2020	us-gaap	Payments Of Dividends PaymentsOfDividends	6234000	USD
CY2019	us-gaap	Payments Of Dividends PaymentsOfDividends	5803000	USD
CY2018	us-gaap	Payments Of Dividends PaymentsOfDividends	5636000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	336876000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	42288000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	56259000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	232180000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-60540000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	89937000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	67425000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	127965000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	38028000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	299605000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	67425000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	127965000	USD
CY2020	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	951000	USD
CY2019	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	2789000	USD
CY2018	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	297000	USD
CY2020	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	52553000	USD
CY2019	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	0	USD
CY2018	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	0	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	26772000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	27871000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	19902000	USD
CY2020	fgbi	Number Of Banking Offices NumberOfBankingOffices	34	office
CY2020	fgbi	Number Of Drive Up Banking Facility NumberOfDriveUpBankingFacility	1	facility
CY2020	fgbi	Number Of Automated Teller Machines NumberOfAutomatedTellerMachines	46	atm
CY2020	fgbi	Maximum Period Of Fair Value Refinement After Closing Date Of Acquisition MaximumPeriodOfFairValueRefinementAfterClosingDateOfAcquisition	P1Y
CY2020	us-gaap	Use Of Estimates UseOfEstimates	<div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-style:italic;font-weight:700;line-height:120%">Use of estimates</span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%">The preparation of financial statements in conformity with generally accepted accounting principles requires Management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenue and expense during the reporting periods. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near-term relate to the determination of the allowance for loan losses, the valuation of real estate acquired in connection with foreclosures or in satisfaction of loans, and the valuation of investment securities. In connection with the determination of the allowance for loan losses and real estate owned, First Guaranty obtains independent appraisals for significant properties.</span></div>
CY2020	fgbi	Period Past Due After Which Evaluation Is Made For Discontinuation Of Interest Accrual On Loan PeriodPastDueAfterWhichEvaluationIsMadeForDiscontinuationOfInterestAccrualOnLoan	P90D
CY2020	fgbi	Period Of Payment Performance After Which Loans Are Returned To Accrual Status PeriodOfPaymentPerformanceAfterWhichLoansAreReturnedToAccrualStatus	P6M
CY2020	fgbi	Period Of Performance After Which Company Evaluates Td Rs That Have Subsequently Been Restructured And Returned To Market Terms PeriodOfPerformanceAfterWhichCompanyEvaluatesTDRsThatHaveSubsequentlyBeenRestructuredAndReturnedToMarketTerms	P6M
CY2020Q4	fgbi	Minimum Balance Of Impaired Loans Over Which Impairment Method Is Applied MinimumBalanceOfImpairedLoansOverWhichImpairmentMethodIsApplied	500000	USD
CY2020	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	1	segment
CY2019Q4	fgbi	Common Stock Dividend Percentage CommonStockDividendPercentage	0.10
CY2020	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	<div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-style:italic;font-weight:700;line-height:120%">Reclassifications</span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%">Certain reclassifications have been made to prior year end financial statements in order to conform to the classification adopted for reporting in 2020.</span></div>
CY2020	us-gaap	Description Of New Accounting Pronouncements Not Yet Adopted DescriptionOfNewAccountingPronouncementsNotYetAdopted	Recent Accounting Pronouncements<div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%">In June 2016, the FASB issued ASU 2016-13, "Financial Instruments- Credit Losses: Measurement of Credit Losses on Financial Instruments". This ASU amends guidance on reporting credit losses for assets held at amortized cost basis and available for sale debt securities. The ASU amendments require the measurement of all expected credit losses for financial assets held at the reporting date be based on historical experience, current conditions, and reasonable and supportable forecasts. The ASU requires assets held at cost basis to reflect the company's current estimate of all expected credit losses. For available for sale debt securities, credit losses should be presented as an allowance rather than as a write-down. In addition, this ASU amends the accounting for purchased financial assets with credit deterioration. On October 16, 2019, the FASB approved an effective date delay applicable to smaller reporting companies until fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. First Guaranty is a smaller reporting company and has delayed the adoption of ASU 2016-13.</span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%">In December 2019, the FASB issued ASU 2019-12, "Simplifying the Accounting for Income Taxes (Topic 740)." The amendments in this ASU simplify the accounting for income taxes by removing certain exceptions to the general principles in the Topic 740. The amendments also improve the consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. The amendments in the ASU are effective for fiscal years and interim periods beginning after December 15, 2020. First Guaranty is currently assessing the impact of adoption of this guidance.</span></div>
CY2020Q4	us-gaap	Business Acquisition Purchase Price Allocation Goodwill Expected Tax Deductible Amount BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount	0	USD
CY2020Q4	fgbi	Federal Reserve Required Cash Deposit FederalReserveRequiredCashDeposit	0	USD
CY2019Q4	fgbi	Federal Reserve Required Cash Deposit FederalReserveRequiredCashDeposit	0	USD
CY2020Q4	fgbi	Number Of Accounts That Exceeded Fdic Insurable Limit NumberOfAccountsThatExceededFDICInsurableLimit	0	account
CY2019Q4	fgbi	Number Of Accounts That Exceeded Fdic Insurable Limit NumberOfAccountsThatExceededFDICInsurableLimit	2	account
CY2019Q4	us-gaap	Cash Uninsured Amount CashUninsuredAmount	5700000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	237728000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	1493000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	673000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	238548000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	337184000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	3352000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	599000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	339937000	USD
CY2020Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	0	USD
CY2020Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	0	USD
CY2020Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	0	USD
CY2020Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	0	USD
CY2019Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	86579000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	382000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	144000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	86817000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	9635000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	9670000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	6994000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	6995000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	67675000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	68412000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	152216000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	152232000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	236520000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	237309000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	237728000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	238548000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions	30	loan
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	141807000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	549000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	10	loan
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	1265000	USD
CY2019	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions No Previous Impairment OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsNoPreviousImpairment	0	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	124000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	40	loan
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	143072000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	673000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions	121	loan
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	131727000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	418000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	22	loan
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	15454000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	181000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	143	loan
CY2019Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	147181000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	599000	USD
CY2019Q4	fgbi	Held To Maturity Securities In Unrealized Loss Positions Less Than Twelve Months Qualitative Disclosure Number Of Positions HeldToMaturitySecuritiesInUnrealizedLossPositionsLessThanTwelveMonthsQualitativeDisclosureNumberOfPositions	9	loan
CY2019Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	11057000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	60000	USD
CY2019Q4	fgbi	Held To Maturity Securities In Unrealized Loss Positions More Than Twelve Months Qualitative Disclosure Number Of Positions HeldToMaturitySecuritiesInUnrealizedLossPositionsMoreThanTwelveMonthsQualitativeDisclosureNumberOfPositions	19	loan
CY2019Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	27358000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	84000	USD
CY2019Q4	us-gaap	Held To Maturity Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions HeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions	28	loan
CY2019Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	38415000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	144000	USD
CY2020Q4	fgbi	Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions SecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions	40	security
CY2020Q4	fgbi	Debt Securities Continuous Unrealized Loss Position Accumulated Loss As Percentage Of All Individual Securities Amortized Cost Basis DebtSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAsPercentageOfAllIndividualSecuritiesAmortizedCostBasis	0.005
CY2020Q4	fgbi	Debt Securities Continuous Unrealized Loss Position Accumulated Loss As Percentage Of Investment Securities Portfolio DebtSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAsPercentageOfInvestmentSecuritiesPortfolio	0.003
CY2020Q4	fgbi	Securities In Unrealized Loss Positions More Than Twelve Months Qualitative Disclosure Number Of Positions SecuritiesInUnrealizedLossPositionsMoreThanTwelveMonthsQualitativeDisclosureNumberOfPositions	10	security
CY2020Q4	fgbi	Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions SecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions	40	security
CY2020Q4	fgbi	Securities In Unrealized Loss Positions More Than Twelve Months Qualitative Disclosure Number Of Positions SecuritiesInUnrealizedLossPositionsMoreThanTwelveMonthsQualitativeDisclosureNumberOfPositions	10	security
CY2020Q4	fgbi	Securities Continuous Unrealized Loss Position Twelve Months Or Longer Amortized Cost Basis SecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerAmortizedCostBasis	1400000	USD
CY2020Q4	fgbi	Securities Continuous Unrealized Loss Position Accumulated Loss SecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	100000	USD
CY2020Q4	fgbi	Debt Securities Held To Maturity Number Of Securities With Other Than Temporary Impairment Loss DebtSecuritiesHeldToMaturityNumberOfSecuritiesWithOtherThanTemporaryImpairmentLoss	1	security
CY2020Q4	fgbi	Debt Securities Held To Maturity Number Of Securities With Other Than Temporary Impairment Loss DebtSecuritiesHeldToMaturityNumberOfSecuritiesWithOtherThanTemporaryImpairmentLoss	1	security
CY2020	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions No Previous Impairment OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsNoPreviousImpairment	100000	USD
CY2020Q4	fgbi	Debt Securities Held To Maturity Original Book Balance DebtSecuritiesHeldToMaturityOriginalBookBalance	100000	USD
CY2018	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions No Previous Impairment OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsNoPreviousImpairment	0	USD
CY2019Q4	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld	0	USD
CY2018Q4	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld	60000	USD
CY2017Q4	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld	60000	USD
CY2020	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions No Previous Impairment OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsNoPreviousImpairment	100000	USD
CY2019	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions No Previous Impairment OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsNoPreviousImpairment	0	USD
CY2018	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions No Previous Impairment OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsNoPreviousImpairment	0	USD
CY2020	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions Additional Credit Losses OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsAdditionalCreditLosses	0	USD
CY2019	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions Additional Credit Losses OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsAdditionalCreditLosses	0	USD
CY2018	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions Additional Credit Losses OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsAdditionalCreditLosses	0	USD
CY2020	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Cash Flows OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsCashFlows	0	USD
CY2019	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Cash Flows OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsCashFlows	0	USD
CY2018	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Cash Flows OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsCashFlows	0	USD
CY2020	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Securities Sold OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsSecuritiesSold	0	USD
CY2019	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Securities Sold OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsSecuritiesSold	60000	USD
CY2018	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Securities Sold OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsSecuritiesSold	0	USD
CY2020Q4	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld	100000	USD
CY2019Q4	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld	0	USD
CY2018Q4	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld	60000	USD
CY2019	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	0	USD
CY2018	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	0	USD
CY2020	us-gaap	Other Than Temporary Impairment Losses Investments Portion In Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherThanTemporaryImpairmentLossesInvestmentsPortionInOtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	0	USD
CY2020Q4	us-gaap	Pledged Financial Instruments Not Separately Reported Securities Pledged PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesPledged	184000000.0	USD
CY2019Q4	us-gaap	Pledged Financial Instruments Not Separately Reported Securities Pledged PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesPledged	212800000	USD
CY2020	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	14700000	USD
CY2019	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	800000	USD
CY2018	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	100000	USD
CY2020	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	100000	USD
CY2019	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	1100000	USD
CY2018	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	1900000	USD
CY2020	fgbi	Proceedsfrom Saleof Debt Securities Availableforsale Tax ProceedsfromSaleofDebtSecuritiesAvailableforsaleTax	3100000	USD
CY2020	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	600000	USD
CY2019	fgbi	Proceedsfrom Saleof Debt Securities Availableforsale Tax ProceedsfromSaleofDebtSecuritiesAvailableforsaleTax	-79000	USD
CY2018	fgbi	Proceedsfrom Saleof Debt Securities Availableforsale Tax ProceedsfromSaleofDebtSecuritiesAvailableforsaleTax	-400000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	394900000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	90500000	USD
CY2018	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	114500000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	2200000	USD
CY2020	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	11700000	USD
CY2019	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	300000	USD
CY2020Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	1849172000	USD
CY2020Q4	fgbi	Financing Receivable Ratio Of Individual Loans Receivable To All Loans Before Unearned Income FinancingReceivableRatioOfIndividualLoansReceivableToAllLoansBeforeUnearnedIncome	1.000
CY2019Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	1528966000	USD
CY2019Q4	fgbi	Financing Receivable Ratio Of Individual Loans Receivable To All Loans Before Unearned Income FinancingReceivableRatioOfIndividualLoansReceivableToAllLoansBeforeUnearnedIncome	1.000
CY2020Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	5037000	USD
CY2019Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	3476000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	1844135000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	1525490000	USD
CY2020Q4	fgbi	Financing Receivables That Are Maturing After One Year Or Less FinancingReceivablesThatAreMaturingAfterOneYearOrLess	265932000	USD
CY2019Q4	fgbi	Financing Receivables That Are Maturing After One Year Or Less FinancingReceivablesThatAreMaturingAfterOneYearOrLess	310455000	USD
CY2020Q4	fgbi	Financing Receivables That Are Maturing After One Year But Not More Than Five Years FinancingReceivablesThatAreMaturingAfterOneYearButNotMoreThanFiveYears	1108617000	USD
CY2019Q4	fgbi	Financing Receivables That Are Maturing After One Year But Not More Than Five Years FinancingReceivablesThatAreMaturingAfterOneYearButNotMoreThanFiveYears	795586000	USD
CY2020Q4	fgbi	Financing Receivables That Are Maturing After Five Years But Not More Than Fifteen Years FinancingReceivablesThatAreMaturingAfterFiveYearsButNotMoreThanFifteenYears	219892000	USD
CY2019Q4	fgbi	Financing Receivables That Are Maturing After Five Years But Not More Than Fifteen Years FinancingReceivablesThatAreMaturingAfterFiveYearsButNotMoreThanFifteenYears	213215000	USD
CY2020Q4	fgbi	Financing Receivables That Are Maturing After Fifteen Years FinancingReceivablesThatAreMaturingAfterFifteenYears	239155000	USD
CY2019Q4	fgbi	Financing Receivables That Are Maturing After Fifteen Years FinancingReceivablesThatAreMaturingAfterFifteenYears	195307000	USD
CY2020Q4	fgbi	Financing Receivable Gross Carrying Amount Net Nonaccrual FinancingReceivableGrossCarryingAmountNetNonaccrual	1833596000	USD
CY2019Q4	fgbi	Financing Receivable Gross Carrying Amount Net Nonaccrual FinancingReceivableGrossCarryingAmountNetNonaccrual	1514563000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	15576000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	14403000	USD
CY2020Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	1849172000	USD
CY2019Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	1528966000	USD
CY2020Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	5037000	USD
CY2019Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	3476000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	1844135000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	1525490000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	60996000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	1788176000	USD
CY2020Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	1849172000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	13091000	USD
CY2020Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	5037000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	1844135000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	41513000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	1487453000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	1844135000	USD
CY2019Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	1528966000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	2639000	USD
CY2019Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	3476000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	1525490000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	15600000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	14400000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	15576000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	14403000	USD
CY2020Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	1849172000	USD
CY2019Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	1528966000	USD
CY2020Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	5037000	USD
CY2019Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	3476000	USD
CY2019	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Additions CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAdditions	3367000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	1525490000	USD
CY2020Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Outstanding Balance CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesOutstandingBalance	9155000	USD
CY2019Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Outstanding Balance CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesOutstandingBalance	10420000	USD
CY2019Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	3647000	USD
CY2018Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	613000	USD
CY2020	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Additions CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAdditions	30000	USD
CY2020	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	785000	USD
CY2019	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	831000	USD
CY2020	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications To From Nonaccretable Difference CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsToFromNonaccretableDifference	0	USD
CY2019	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications To From Nonaccretable Difference CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsToFromNonaccretableDifference	498000	USD
CY2020Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	2892000	USD
CY2019Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	3647000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	10929000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	2427000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	1139000	USD
CY2020	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	14877000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	24518000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	10776000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	5264000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	557000	USD
CY2019	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	4860000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	10929000	USD
CY2017Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	9225000	USD
CY2018	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	1889000	USD
CY2018	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	2086000	USD
CY2018	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	1354000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	10776000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	2643000	USD
CY2020Q4	fgbi	Financing Receivable Allowance For Credit Losses Individually Evaluated For Purchased Credit Impairment FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForPurchasedCreditImpairment	0	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	21875000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	24518000	USD
CY2020Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	15898000	USD
CY2020Q4	fgbi	Financing Receivable Individually Evaluated For Purchased Credit Impairment FinancingReceivableIndividuallyEvaluatedForPurchasedCreditImpairment	9155000	USD
CY2020Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	1824119000	USD
CY2020Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	1849172000	USD
CY2020Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	5037000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	1844135000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	2024000	USD
CY2019Q4	fgbi	Financing Receivable Allowance For Credit Losses Individually Evaluated For Purchased Credit Impairment FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForPurchasedCreditImpairment	0	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	8905000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	10929000	USD
CY2019Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	20732000	USD
CY2019Q4	fgbi	Financing Receivable Individually Evaluated For Purchased Credit Impairment FinancingReceivableIndividuallyEvaluatedForPurchasedCreditImpairment	10420000	USD
CY2019Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	1497814000	USD
CY2019Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	1528966000	USD
CY2019Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	3476000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	1525490000	USD
CY2020Q4	fgbi	Financing Receivable Recorded Investment Not Accruing Interest FinancingReceivableRecordedInvestmentNotAccruingInterest	15600000	USD
CY2019Q4	fgbi	Financing Receivable Recorded Investment Not Accruing Interest FinancingReceivableRecordedInvestmentNotAccruingInterest	14400000	USD
CY2018Q4	fgbi	Financing Receivable Recorded Investment Not Accruing Interest FinancingReceivableRecordedInvestmentNotAccruingInterest	8700000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	13100000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	2600000	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	100000	USD
CY2020Q4	fgbi	Financing Receivable Average Recorded Investment Nonaccrual Status FinancingReceivableAverageRecordedInvestmentNonaccrualStatus	19800000	USD
CY2019Q4	fgbi	Financing Receivable Average Recorded Investment Nonaccrual Status FinancingReceivableAverageRecordedInvestmentNonaccrualStatus	12000000.0	USD
CY2018Q4	fgbi	Financing Receivable Average Recorded Investment Nonaccrual Status FinancingReceivableAverageRecordedInvestmentNonaccrualStatus	8900000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	5413000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	5575000	USD
CY2020	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	5703000	USD
CY2020	us-gaap	Impaired Financing Receivable With No Related Allowance Interest Income Accrual Method ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod	128000	USD
CY2020	us-gaap	Impaired Financing Receivable With No Related Allowance Interest Income Cash Basis Method ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod	119000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	10485000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	10531000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	2643000	USD
CY2020	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	9500000	USD
CY2020	us-gaap	Impaired Financing Receivable With Related Allowance Interest Income Accrual Method ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod	144000	USD
CY2020	us-gaap	Impaired Financing Receivable With Related Allowance Interest Income Cash Basis Method ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod	142000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	15898000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	16106000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	2643000	USD
CY2020	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	15203000	USD
CY2020	us-gaap	Impaired Financing Receivable Interest Income Accrual Method ImpairedFinancingReceivableInterestIncomeAccrualMethod	272000	USD
CY2020	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	261000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	15383000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	15548000	USD
CY2019	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	16853000	USD
CY2019	us-gaap	Impaired Financing Receivable With No Related Allowance Interest Income Accrual Method ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod	793000	USD
CY2019	us-gaap	Impaired Financing Receivable With No Related Allowance Interest Income Cash Basis Method ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod	777000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	5349000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	5698000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	2024000	USD
CY2019	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	5695000	USD
CY2019	us-gaap	Impaired Financing Receivable With Related Allowance Interest Income Accrual Method ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod	275000	USD
CY2019	us-gaap	Impaired Financing Receivable With Related Allowance Interest Income Cash Basis Method ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod	289000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	20732000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	21246000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	2024000	USD
CY2019	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	22548000	USD
CY2019	us-gaap	Impaired Financing Receivable Interest Income Accrual Method ImpairedFinancingReceivableInterestIncomeAccrualMethod	1068000	USD
CY2019	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	1066000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	1	contract
CY2019	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	1	contract
CY2020Q4	fgbi	Financing Receivable Troubled Debt Restructuring Number Of Contracts FinancingReceivableTroubledDebtRestructuringNumberOfContracts	1	loan
CY2020Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	3591000	USD
CY2019Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	0	USD
CY2019Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	0	USD
CY2020	fgbi	Financing Receivable Modifications Additions FinancingReceivableModificationsAdditions	3613000	USD
CY2020	us-gaap	Financing Receivables Impaired Troubled Debt Restructuring Write Down FinancingReceivablesImpairedTroubledDebtRestructuringWriteDown	0	USD
CY2020	fgbi	Financing Receivable Modifications Transferred To Other Real Estate FinancingReceivableModificationsTransferredToOtherRealEstate	0	USD
CY2020	fgbi	Financing Receivable Modifications Paydowns FinancingReceivableModificationsPaydowns	22000	USD
CY2020	fgbi	Financing Receivable Modifications Construction To Permanent Financing FinancingReceivableModificationsConstructionToPermanentFinancing	0	USD
CY2020	fgbi	Financing Receivable Modifications Restructured To Market Terms FinancingReceivableModificationsRestructuredToMarketTerms	0	USD
CY2020	fgbi	Financing Receivable Modifications Other Adjustments FinancingReceivableModificationsOtherAdjustments	0	USD
CY2020Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	3591000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	500000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	98159000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	92505000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	38267000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	36041000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	59892000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	56464000	USD
CY2020	us-gaap	Depreciation Depreciation	2800000	USD
CY2019	us-gaap	Depreciation Depreciation	2300000	USD
CY2018	us-gaap	Depreciation Depreciation	2100000	USD
CY2020Q4	us-gaap	Capitalized Contract Cost Net CapitalizedContractCostNet	55000	USD
CY2019Q4	us-gaap	Capitalized Contract Cost Net CapitalizedContractCostNet	91000	USD
CY2018Q4	us-gaap	Capitalized Contract Cost Net CapitalizedContractCostNet	54000	USD
CY2020	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	0	USD
CY2019Q4	us-gaap	Goodwill Goodwill	12900000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	12900000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	18092000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	11505000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	6587000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	17824000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	10658000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	7166000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	700000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	400000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	576000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	576000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	644000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	576000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	576000	USD
CY2020Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	2645000	USD
CY2019Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	4879000	USD
CY2020Q4	fgbi	Other Real Estate Foreclosed Assets And Repossessed Assets Allowance For Credit Loss OtherRealEstateForeclosedAssetsAndRepossessedAssetsAllowanceForCreditLoss	405000	USD
CY2019Q4	fgbi	Other Real Estate Foreclosed Assets And Repossessed Assets Allowance For Credit Loss OtherRealEstateForeclosedAssetsAndRepossessedAssetsAllowanceForCreditLoss	0	USD
CY2020Q4	us-gaap	Other Real Estate And Foreclosed Assets OtherRealEstateAndForeclosedAssets	2240000	USD
CY2019Q4	us-gaap	Other Real Estate And Foreclosed Assets OtherRealEstateAndForeclosedAssets	4879000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	355093000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	125678000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	108380000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	113745000	USD
CY2020Q4	fgbi	Time Deposit Maturities After Year Four TimeDepositMaturitiesAfterYearFour	22733000	USD
CY2020Q4	us-gaap	Time Deposits TimeDeposits	725629000	USD
CY2020Q4	us-gaap	Interest Bearing Domestic Deposit Brokered InterestBearingDomesticDepositBrokered	3400000	USD
CY2020Q4	fgbi	Time Deposits250000 Or More TimeDeposits250000OrMore	248800000	USD
CY2019Q4	fgbi	Time Deposits250000 Or More TimeDeposits250000OrMore	290300000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	50000000	USD
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	13079000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	6121000	USD
CY2019Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	6840000	USD
CY2020Q4	us-gaap	Lines Of Credit Current LinesOfCreditCurrent	0	USD
CY2019Q4	us-gaap	Lines Of Credit Current LinesOfCreditCurrent	0	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	56121000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	19919000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	56100000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	19900000	USD
CY2020Q4	us-gaap	Line Of Credit Facility Maximum Borrowing Capacity LineOfCreditFacilityMaximumBorrowingCapacity	6500000	USD
CY2020Q4	us-gaap	Lines Of Credit Current LinesOfCreditCurrent	0	USD
CY2020Q4	us-gaap	Line Of Credit Facility Remaining Borrowing Capacity LineOfCreditFacilityRemainingBorrowingCapacity	297200000	USD
CY2019Q4	us-gaap	Line Of Credit Facility Remaining Borrowing Capacity LineOfCreditFacilityRemainingBorrowingCapacity	278800000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	56121000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	19919000	USD
CY2018Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	0	USD
CY2020	us-gaap	Shortterm Debt Maximum Monthend Outstanding Amount ShorttermDebtMaximumMonthendOutstandingAmount	57048000	USD
CY2019	us-gaap	Shortterm Debt Maximum Monthend Outstanding Amount ShorttermDebtMaximumMonthendOutstandingAmount	19919000	USD
CY2018	us-gaap	Shortterm Debt Maximum Monthend Outstanding Amount ShorttermDebtMaximumMonthendOutstandingAmount	37000000	USD
CY2020	us-gaap	Shortterm Debt Average Outstanding Amount ShorttermDebtAverageOutstandingAmount	48277000	USD
CY2019	us-gaap	Shortterm Debt Average Outstanding Amount ShorttermDebtAverageOutstandingAmount	3320000	USD
CY2018	us-gaap	Shortterm Debt Average Outstanding Amount ShorttermDebtAverageOutstandingAmount	7119000	USD
CY2020	us-gaap	Short Term Debt Weighted Average Interest Rate Over Time ShortTermDebtWeightedAverageInterestRateOverTime	0.0095
CY2020Q1	fgbi	Banking Regulation Community Bank Leverage Ratio BankingRegulationCommunityBankLeverageRatio	0.09
CY2019	us-gaap	Short Term Debt Weighted Average Interest Rate Over Time ShortTermDebtWeightedAverageInterestRateOverTime	0.0200
CY2018	us-gaap	Short Term Debt Weighted Average Interest Rate Over Time ShortTermDebtWeightedAverageInterestRateOverTime	0.0221
CY2020Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0.0089
CY2019Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0.0200
CY2018Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0
CY2020Q4	us-gaap	Long Term Debt LongTermDebt	60500000	USD
CY2020Q4	us-gaap	Banking Regulation Capital Conservation Buffer Capital Conserved Minimum BankingRegulationCapitalConservationBufferCapitalConservedMinimum	0.025
CY2020Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	10000000000	USD
CY2020Q2	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.08
CY2020	fgbi	Banking Regulation Increase Community Bank Leverage Ratio BankingRegulationIncreaseCommunityBankLeverageRatio	0.085
CY2020	fgbi	Banking Regulation Community Bank Leverage Ratio BankingRegulationCommunityBankLeverageRatio	0.09
CY2020	fgbi	Percentage Of Outstanding Capital Stock Maximum PercentageOfOutstandingCapitalStockMaximum	0.50
CY2020	us-gaap	Undistributed Earnings UndistributedEarnings	5700000	USD
CY2020Q4	us-gaap	Equity Restrictions EquityRestrictions	223100000	USD
CY2019Q4	us-gaap	Notes Receivable Related Parties NotesReceivableRelatedParties	61820000	USD
CY2018Q4	us-gaap	Notes Receivable Related Parties NotesReceivableRelatedParties	63907000	USD
CY2020	us-gaap	Increase Decrease In Notes Receivable Related Parties IncreaseDecreaseInNotesReceivableRelatedParties	17579000	USD
CY2019	us-gaap	Increase Decrease In Notes Receivable Related Parties IncreaseDecreaseInNotesReceivableRelatedParties	-2087000	USD
CY2020Q4	us-gaap	Notes Receivable Related Parties NotesReceivableRelatedParties	79399000	USD
CY2019Q4	us-gaap	Notes Receivable Related Parties NotesReceivableRelatedParties	61820000	USD
CY2020	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	2465000	USD
CY2019	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	1972000	USD
CY2020	fgbi	Defined Contribution Plan Minimum Annual Contributions Per Employee Percent DefinedContributionPlanMinimumAnnualContributionsPerEmployeePercent	0.01
CY2020	us-gaap	Defined Contribution Plan Maximum Annual Contributions Per Employee Percent DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent	0.20
CY2020	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent DefinedContributionPlanEmployerMatchingContributionPercent	0.06
CY2020	fgbi	Defined Contribution Plan Maximum Matching Percentage DefinedContributionPlanMaximumMatchingPercentage	1
CY2020	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	173000	USD
CY2019	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	149000	USD
CY2018	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	292000	USD
CY2018	us-gaap	Employee Stock Ownership Plan Esop Cash Contributions To Esop EmployeeStockOwnershipPlanESOPCashContributionsToESOP	0	USD
CY2019	us-gaap	Employee Stock Ownership Plan Esop Cash Contributions To Esop EmployeeStockOwnershipPlanESOPCashContributionsToESOP	0	USD
CY2020	us-gaap	Employee Stock Ownership Plan Esop Cash Contributions To Esop EmployeeStockOwnershipPlanESOPCashContributionsToESOP	0	USD
CY2020Q4	us-gaap	Employee Stock Ownership Plan Esop Shares In Esop EmployeeStockOwnershipPlanESOPSharesInESOP	2770	shares
CY2020	us-gaap	Legal Fees LegalFees	2919000	USD
CY2019	us-gaap	Legal Fees LegalFees	2648000	USD
CY2018	us-gaap	Legal Fees LegalFees	2362000	USD
CY2019	us-gaap	Supplies Expense SuppliesExpense	674000	USD
CY2018	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	1692000	USD
CY2020	fgbi	Automated Teller Machine Fees AutomatedTellerMachineFees	1332000	USD
CY2019	fgbi	Automated Teller Machine Fees AutomatedTellerMachineFees	1217000	USD
CY2018	fgbi	Automated Teller Machine Fees AutomatedTellerMachineFees	1214000	USD
CY2020	us-gaap	Marketing Expense MarketingExpense	1046000	USD
CY2019	us-gaap	Marketing Expense MarketingExpense	1456000	USD
CY2018	us-gaap	Marketing Expense MarketingExpense	1329000	USD
CY2020	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	1251000	USD
CY2019	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	1094000	USD
CY2018	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	1066000	USD
CY2020	us-gaap	Supplies Expense SuppliesExpense	921000	USD
CY2018	us-gaap	Supplies Expense SuppliesExpense	562000	USD
CY2020	fgbi	Software Expense And Amortization SoftwareExpenseAndAmortization	2354000	USD
CY2019	fgbi	Software Expense And Amortization SoftwareExpenseAndAmortization	1308000	USD
CY2018	fgbi	Software Expense And Amortization SoftwareExpenseAndAmortization	1119000	USD
CY2020	us-gaap	Travel And Entertainment Expense TravelAndEntertainmentExpense	726000	USD
CY2019	us-gaap	Travel And Entertainment Expense TravelAndEntertainmentExpense	908000	USD
CY2018	us-gaap	Travel And Entertainment Expense TravelAndEntertainmentExpense	978000	USD
CY2020	fgbi	Telephone Expense TelephoneExpense	256000	USD
CY2019	fgbi	Telephone Expense TelephoneExpense	193000	USD
CY2018	fgbi	Telephone Expense TelephoneExpense	208000	USD
CY2020	fgbi	Amortization Of Core Deposits AmortizationOfCoreDeposits	712000	USD
CY2019	fgbi	Amortization Of Core Deposits AmortizationOfCoreDeposits	390000	USD
CY2018	fgbi	Amortization Of Core Deposits AmortizationOfCoreDeposits	545000	USD
CY2020	fgbi	Donations Donations	393000	USD
CY2019	fgbi	Donations Donations	603000	USD
CY2018	fgbi	Donations Donations	380000	USD
CY2020	fgbi	Net Costs From Other Real Estate And Repossessions NetCostsFromOtherRealEstateAndRepossessions	1653000	USD
CY2019	fgbi	Net Costs From Other Real Estate And Repossessions NetCostsFromOtherRealEstateAndRepossessions	422000	USD
CY2018	fgbi	Net Costs From Other Real Estate And Repossessions NetCostsFromOtherRealEstateAndRepossessions	186000	USD
CY2020	fgbi	Regulatory Assessment RegulatoryAssessment	1716000	USD
CY2019	fgbi	Regulatory Assessment RegulatoryAssessment	683000	USD
CY2018	fgbi	Regulatory Assessment RegulatoryAssessment	941000	USD
CY2020	fgbi	Non Interest Expense Other NonInterestExpenseOther	2980000	USD
CY2019	fgbi	Non Interest Expense Other NonInterestExpenseOther	2536000	USD
CY2018	fgbi	Non Interest Expense Other NonInterestExpenseOther	2204000	USD
CY2020	us-gaap	Other Noninterest Expense OtherNoninterestExpense	20724000	USD
CY2019	us-gaap	Other Noninterest Expense OtherNoninterestExpense	16104000	USD
CY2018	us-gaap	Other Noninterest Expense OtherNoninterestExpense	14786000	USD
CY2020	us-gaap	Advertising Expense AdvertisingExpense	400000	USD
CY2019	us-gaap	Advertising Expense AdvertisingExpense	800000	USD
CY2018	us-gaap	Advertising Expense AdvertisingExpense	900000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	8964000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	3770000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	3929000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-3745000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	5219000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-114000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-467000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	5219000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3656000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3462000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	5363000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	3758000	USD
CY2018	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	3712000	USD
CY2020	fgbi	Income Tax Reconciliation Tax Exempt Income Municipal Income IncomeTaxReconciliationTaxExemptIncomeMunicipalIncome	124000	USD
CY2019	fgbi	Income Tax Reconciliation Tax Exempt Income Municipal Income IncomeTaxReconciliationTaxExemptIncomeMunicipalIncome	140000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	1720000	USD
CY2020Q4	fgbi	Deferred Tax Assets Other Real Estate Owned DeferredTaxAssetsOtherRealEstateOwned	239000	USD
CY2018	fgbi	Income Tax Reconciliation Tax Exempt Income Municipal Income IncomeTaxReconciliationTaxExemptIncomeMunicipalIncome	166000	USD
CY2020	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	-20000	USD
CY2019	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	38000	USD
CY2018	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	-84000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3656000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3462000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	4748000	USD
CY2019Q4	fgbi	Deferred Tax Assets Other Real Estate Owned DeferredTaxAssetsOtherRealEstateOwned	257000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	0	USD
CY2019Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	0	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	1190000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	1282000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	581000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	508000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	6758000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	3767000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	1952000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	2010000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	1214000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	1359000	USD
CY2020Q4	fgbi	Deferred Tax Liabilities Unrealized Gains On Availablefor Sale Securities DeferredTaxLiabilitiesUnrealizedGainsOnAvailableforSaleSecurities	172000	USD
CY2019Q4	fgbi	Deferred Tax Liabilities Unrealized Gains On Availablefor Sale Securities DeferredTaxLiabilitiesUnrealizedGainsOnAvailableforSaleSecurities	578000	USD
CY2020Q4	fgbi	Deferred Tax Liabilities Discount On Purchased Loans DeferredTaxLiabilitiesDiscountOnPurchasedLoans	161000	USD
CY2019Q4	fgbi	Deferred Tax Liabilities Discount On Purchased Loans DeferredTaxLiabilitiesDiscountOnPurchasedLoans	267000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	625000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	670000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	4124000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	4884000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	2634000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Expense UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense	0	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	1117000	USD
CY2020Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	5700000	USD
CY2019Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	6100000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Expense UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense	0	USD
CY2019	us-gaap	Unrecognized Tax Benefits Income Tax Penalties Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense	0	USD
CY2018	us-gaap	Unrecognized Tax Benefits Income Tax Penalties Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Income Tax Penalties Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Expense UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense	0	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	0	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	0	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	0	USD
CY2018Q4	us-gaap	Income Tax Examination Penalties Accrued IncomeTaxExaminationPenaltiesAccrued	0	USD
CY2020Q4	us-gaap	Income Tax Examination Penalties Accrued IncomeTaxExaminationPenaltiesAccrued	0	USD
CY2019Q4	us-gaap	Income Tax Examination Penalties Accrued IncomeTaxExaminationPenaltiesAccrued	0	USD
CY2020	fgbi	Extension Period Of Majority Of Short Term Borrowing ExtensionPeriodOfMajorityOfShortTermBorrowing	P1Y
CY2020	fgbi	Maximum Extension Period Of Short Term Borrowing MaximumExtensionPeriodOfShortTermBorrowing	P3Y
CY2020	us-gaap	Loss Contingency Loss In Period LossContingencyLossInPeriod	0	USD
CY2018	us-gaap	Loss Contingency Loss In Period LossContingencyLossInPeriod	0	USD
CY2019	us-gaap	Loss Contingency Loss In Period LossContingencyLossInPeriod	0	USD
CY2019Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	9398000	USD
CY2018Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	4761000	USD
CY2020	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	0	USD
CY2019	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	0	USD
CY2020	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	256000	USD
CY2019	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	146000	USD
CY2020	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases Sales Issuances Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements	5361000	USD
CY2019	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases Sales Issuances Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements	4491000	USD
CY2020	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Net FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet	11174000	USD
CY2019	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Net FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet	0	USD
CY2020Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	26189000	USD
CY2019Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	9398000	USD
CY2020Q4	fgbi	Percentage Of Entity Deposits PercentageOfEntityDeposits	0.330
CY2020	fgbi	Number Of Deposits Of Depositing Authorities NumberOfDepositsOfDepositingAuthorities	1	deposit
CY2020Q4	fgbi	Public Fund Deposits PublicFundDeposits	715300000	USD

Files In Submission

Name	View Source	Status
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$FGBI
First Guaranty Bancshares, Inc. Stock $fgbi

2020 Form 10-K Financial Statement

#000140853421000014 Filed on March 16, 2021

Income Statement

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$FGBI First Guaranty Bancshares, Inc. Stock $fgbi

2020 Form 10-K Financial Statement

#000140853421000014 Filed on March 16, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$FGBI
First Guaranty Bancshares, Inc. Stock $fgbi