XML 47 R36.htm IDEA: XBRL DOCUMENT
v3.20.2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Thousands |  | 3 Months Ended | 6 Months Ended |
--- | --- | --- | --- | ---
Jan. 01, 2020 USD ($) | Jun. 30, 2020 USD ($) subsidary Family Residentialhouse | Jun. 30, 2019 USD ($) | Jun. 30, 2020 USD ($) subsidary Family Residentialhouse | Jun. 30, 2019 USD ($) | Dec. 31, 2019 USD ($)
Property, Plant and Equipment [Line Items] |  |  |  |  |  |
Number of subsidiaries | subsidary |  | 6 |  | 6 |  |
Provision for loan losses |  | $ 12,100 | $ 575 | $ 13,500 | $ 1,150 |
Decrease to retained earnings |  | $ 97,788 |  | 97,788 |  | $ 98,239
Retained earnings, net of tax |  |  |  | $ 955 |  |
Number of families secured by loans of real estate | Family |  | 4 |  | 4 |  |
Number of housing units secured by loans from segment | Residentialhouse |  | 5 |  | 5 |  |
Paycheck Protection Program Loans |  |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |  |
Percentage of government guaranteed loans |  | 100.00% |  | 100.00% |  |
Accounting Standards Update 2016-13 |  |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |  |
Increase to allowance for credit losses | $ 4,548 |  |  |  |  |
Increase to allowance for credit losses, percent | 28.10% |  |  |  |  |
Provision for loan losses |  | $ 13,500 |  | $ 13,500 |  |
Accounting Standards Update 2016-13 | Cumulative Effect | Revision of Prior Period, Adjustment |  |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |  |
Decrease to retained earnings |  | $ (3,593) |  | (3,593) |  |
Retained earnings, net of tax |  |  |  | $ 955 |  |

X
- Definition Cumulative effect on retained earnings, tax effect. + References No definition available. + Details
Name: | gnty_CumulativeEffectOnRetainedEarningsTaxEffect
Namespace Prefix: | gnty_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Increase (decrease) to allowance for credit losses, percent. + References No definition available. + Details
Name: | gnty_IncreaseDecreaseToAllowanceForCreditLossesPercent
Namespace Prefix: | gnty_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of families secured by loans of real estate. + References No definition available. + Details
Name: | gnty_NumberOfFamiliesSecuredByLoansOfRealEstate
Namespace Prefix: | gnty_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of housing units secured by loans from segment. + References No definition available. + Details
Name: | gnty_NumberOfHousingUnitsSecuredByLoansFromSegment
Namespace Prefix: | gnty_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Subsidiaries + References No definition available. + Details
Name: | gnty_NumberOfSubsidiaries
Namespace Prefix: | gnty_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of government guaranteed loans. + References No definition available. + Details
Name: | gnty_PercentageOfGovernmentGuaranteedLoans
Namespace Prefix: | gnty_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of increase (decrease) of allowance reserve for credit loss. + References No definition available. + Details
Name: | us-gaap_AllowanceForLoanAndLeaseLossesPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense related to estimated loss from loan and lease transactions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.11) -URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524 + Details
Name: | us-gaap_ProvisionForLoanAndLeaseLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cumulative amount of the reporting entity's undistributed earnings or deficit. + 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(30)(a)(3)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 65 -Paragraph 15 -Subparagraph (g)(2) -URI http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(23)(a)(4)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (h)(2) -URI http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (g)(2)(i) -URI http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641 + Details
Name: | us-gaap_RetainedEarningsAccumulatedDeficit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LoansInsuredOrGuaranteedByGovernmentAuthoritiesAxis=us-gaap_LoansInsuredOrGuaranteedByUsGovernmentAuthoritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201613Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CumulativeEffectPeriodOfAdoptionAxis=srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RestatementAxis=srt_RestatementAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |