Note 16 - Disclosures About Fair Value of Assets and Liabilities - Fair Value of Financial Instruments (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Interest-bearing demand deposits in other financial institutions	$ 142,056,538	$ 87,557,842
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	148,422,908	92,671,909
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Interest-bearing demand deposits in other financial institutions	4,760,089	250,000
Federal Home Loan Bank stock	3,896,900	3,757,500
Mortgage loans held for sale	11,359,174	2,786,564
Interest receivable	4,060,795	3,511,875
Deposits	938,672,541	821,406,532
FHLB advances	66,000,000	65,000,000
Interest payable	932,172	793,746
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Loans, net	742,149,271	720,732,402
Note payable to bank	0	11,200,000
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Subordinated Debentures Issued to Capital Trusts [Member]
Subordinated debentures	15,465,000	15,465,000
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Subordinated Notes, Net [Member]
Subordinated debentures	19,564,131	0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	148,422,908	92,671,909
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Interest-bearing demand deposits in other financial institutions	4,771,605	250,315
Federal Home Loan Bank stock	3,896,900	3,757,500
Mortgage loans held for sale	11,626,174	2,786,564
Interest receivable	4,060,795	3,511,875
Deposits	939,806,149	822,046,988
FHLB advances	66,089,183	65,015,635
Interest payable	932,172	793,746
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Loans, net	737,701,011	718,594,936
Note payable to bank	0	11,200,000
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Subordinated Debentures Issued to Capital Trusts [Member]
Subordinated debentures	15,465,000	15,465,000
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Subordinated Notes, Net [Member]
Subordinated debentures	$ 25,608,997	$ 0

Fair value portion of interest payable.

No definition available.

Name:	gfed_InterestPayableFairValueDisclosure
Namespace Prefix:	gfed_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of interest receivable.

+ References

No definition available.

+ Details

Name:	gfed_InterestReceivableFairValueDisclosure
Namespace Prefix:	gfed_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

No definition available.

+ Details

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

- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

+ References

No definition available.

+ Details

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

- Definition

Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

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

- Definition

Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13(3)(a))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- Definition

For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=117340910&loc=d3e59706-112781

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.2)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- Definition

Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

+ References

No definition available.

+ Details

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

- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI http://asc.fasb.org/subtopic&trid=2196772

+ Details

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

- Definition

Fair value portion of mortgage loans held-for-sale.

+ References

No definition available.

+ Details

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

- Definition

Fair value portion of notes payable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19,20,22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=gfed_SubordinatedDebenturesIssuedToCapitalTrustsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=gfed_SubordinatedNotesNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: