XML 105 R89.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Subordinated Debentures - Schedule of Subordinated Debentures (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2021 | Dec. 31, 2020
Terms of Subordinated Debentures |  |
Balance | $ 132,620 | $ 139,959
Subordinated debentures owed to trust subsidiaries |  |
Terms of Subordinated Debentures |  |
Balance | 132,620 |
First Company Statutory Trust 2001 | Subordinated debentures owed to trust subsidiaries |  |
Terms of Subordinated Debentures |  |
Balance | $ 3,521 |
Rate | 3.432% |
Rate Structure | 3.30% |
First Company Statutory Trust 2003 | Subordinated debentures owed to trust subsidiaries |  |
Terms of Subordinated Debentures |  |
Balance | $ 2,587 |
Rate | 3.47% |
Rate Structure | 3.25% |
Glacier Capital Trust II | Subordinated debentures owed to trust subsidiaries |  |
Terms of Subordinated Debentures |  |
Balance | $ 46,393 |
Rate | 2.874% |
Rate Structure | 2.75% |
Citizens (ID) Statutory Trust I | Subordinated debentures owed to trust subsidiaries |  |
Terms of Subordinated Debentures |  |
Balance | $ 5,155 |
Rate | 2.866% |
Rate Structure | 2.65% |
Glacier Capital Trust III | Subordinated debentures owed to trust subsidiaries |  |
Terms of Subordinated Debentures |  |
Balance | $ 36,083 |
Rate | 1.414% |
Rate Structure | 1.29% |
Glacier Capital Trust IV | Subordinated debentures owed to trust subsidiaries |  |
Terms of Subordinated Debentures |  |
Balance | $ 30,928 |
Rate | 1.773% |
Rate Structure | 1.57% |
Bank of the San Juans Bancorporation Trust I | Subordinated debentures owed to trust subsidiaries |  |
Terms of Subordinated Debentures |  |
Balance | $ 2,041 |
Rate | 1.991% |
Rate Structure | 1.82% |
FNB (UT) Statutory Trust I | Subordinated debentures owed to trust subsidiaries |  |
Terms of Subordinated Debentures |  |
Balance | $ 4,124 |
Rate | 3.32% |
Rate Structure | 3.10% |
FNB (UT) Statutory Trust II | Subordinated debentures owed to trust subsidiaries |  |
Terms of Subordinated Debentures |  |
Balance | $ 1,788 |
Rate | 1.923% |
Rate Structure | 1.72% |

X
- Definition Terms of subordinated debentures. + References No definition available. + Details
Name: | gbci_TermsOfSubordinatedDebenturesAbstract
Namespace Prefix: | gbci_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123466204&loc=SL6036836-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets. + 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)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 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(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 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)(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 4: 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(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_SubordinatedDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=gbci_JuniorSubordinatedDebentureOwedtoUnconsolidatedSubsidiaryTrustMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbci_FirstCompanyStatutoryTrust2001Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbci_FirstCompanyStatutoryTrust2003Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbci_GlacierCapitalTrustIiMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbci_CitizensIdStatutoryTrustIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbci_GlacierCapitalTrustIiiMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbci_GlacierCapitalTrustIvMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbci_BankOfSanJuansBancorporationTrustIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbci_FNBUTStatutoryTrustIMemberMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbci_FNBUTStatutoryTrustIIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |