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v2.4.1.9

Regulatory Capital (Details) (USD $) In Thousands, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013
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Total capital (to risk-weighted assets) |  |
Actual, Amount | $ 1,065,282us-gaap_Capital | $ 1,005,980us-gaap_Capital
Actual, Ratio | 18.93%us-gaap_CapitalToRiskWeightedAssets | 18.97%us-gaap_CapitalToRiskWeightedAssets
Minimum capital requirement, Amount | 450,240us-gaap_CapitalRequiredForCapitalAdequacy | 424,322us-gaap_CapitalRequiredForCapitalAdequacy
Minimum capital requirement, Ratio | 8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets | 8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
Well capitalized requirement, Amount | 562,800us-gaap_CapitalRequiredToBeWellCapitalized | 530,402us-gaap_CapitalRequiredToBeWellCapitalized
Well capitalized requirement, Ratio | 10.00%us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets | 10.00%us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Tier 1 capital (to risk-weighted assets) |  |
Actual, Amount | 994,197us-gaap_TierOneRiskBasedCapital | 938,887us-gaap_TierOneRiskBasedCapital
Actual, Ratio | 17.67%us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets | 17.70%us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets
Minimum capital requirement, Amount | 225,120us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy | 212,161us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy
Minimum capital requirement, Ratio | 4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets | 4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
Well capitalized requirement, Amount | 337,680us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized | 318,241us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized
Well capitalized requirement, Ratio | 6.00%us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets | 6.00%us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Tier 1 capital (to average assets) |  |
Actual, Amount | 994,197us-gaap_TierOneLeverageCapital | 938,887us-gaap_TierOneLeverageCapital
Actual, Ratio | 12.45%us-gaap_TierOneLeverageCapitalToAverageAssets | 12.11%us-gaap_TierOneLeverageCapitalToAverageAssets
Minimum capital requirement, Amount | 319,505us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy | 310,082us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy
Minimum capital requirement, Ratio | 4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets | 4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets
Glacier Bank |  |
Total capital (to risk-weighted assets) |  |
Actual, Amount | 1,023,669us-gaap_Capital / dei_LegalEntityAxis = gbci_GlacierBankMember | 948,618us-gaap_Capital / dei_LegalEntityAxis = gbci_GlacierBankMember
Actual, Ratio | 18.25%us-gaap_CapitalToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember | 17.93%us-gaap_CapitalToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember
Minimum capital requirement, Amount | 448,739us-gaap_CapitalRequiredForCapitalAdequacy / dei_LegalEntityAxis = gbci_GlacierBankMember | 423,235us-gaap_CapitalRequiredForCapitalAdequacy / dei_LegalEntityAxis = gbci_GlacierBankMember
Minimum capital requirement, Ratio | 8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember | 8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember
Well capitalized requirement, Amount | 560,924us-gaap_CapitalRequiredToBeWellCapitalized / dei_LegalEntityAxis = gbci_GlacierBankMember | 529,044us-gaap_CapitalRequiredToBeWellCapitalized / dei_LegalEntityAxis = gbci_GlacierBankMember
Well capitalized requirement, Ratio | 10.00%us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember | 10.00%us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember
Tier 1 capital (to risk-weighted assets) |  |
Actual, Amount | 952,815us-gaap_TierOneRiskBasedCapital / dei_LegalEntityAxis = gbci_GlacierBankMember | 881,692us-gaap_TierOneRiskBasedCapital / dei_LegalEntityAxis = gbci_GlacierBankMember
Actual, Ratio | 16.99%us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember | 16.67%us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember
Minimum capital requirement, Amount | 224,370us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy / dei_LegalEntityAxis = gbci_GlacierBankMember | 211,618us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy / dei_LegalEntityAxis = gbci_GlacierBankMember
Minimum capital requirement, Ratio | 4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember | 4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember
Well capitalized requirement, Amount | 336,554us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized / dei_LegalEntityAxis = gbci_GlacierBankMember | 317,426us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized / dei_LegalEntityAxis = gbci_GlacierBankMember
Well capitalized requirement, Ratio | 6.00%us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember | 6.00%us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets / dei_LegalEntityAxis = gbci_GlacierBankMember
Tier 1 capital (to average assets) |  |
Actual, Amount | 952,815us-gaap_TierOneLeverageCapital / dei_LegalEntityAxis = gbci_GlacierBankMember | 881,692us-gaap_TierOneLeverageCapital / dei_LegalEntityAxis = gbci_GlacierBankMember
Actual, Ratio | 12.03%us-gaap_TierOneLeverageCapitalToAverageAssets / dei_LegalEntityAxis = gbci_GlacierBankMember | 11.44%us-gaap_TierOneLeverageCapitalToAverageAssets / dei_LegalEntityAxis = gbci_GlacierBankMember
Minimum capital requirement, Amount | 316,938us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy / dei_LegalEntityAxis = gbci_GlacierBankMember | 308,281us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy / dei_LegalEntityAxis = gbci_GlacierBankMember
Minimum capital requirement, Ratio | 4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets / dei_LegalEntityAxis = gbci_GlacierBankMember | 4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets / dei_LegalEntityAxis = gbci_GlacierBankMember
Well capitalized requirement, Amount | $ 396,173us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized / dei_LegalEntityAxis = gbci_GlacierBankMember | $ 385,351us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized / dei_LegalEntityAxis = gbci_GlacierBankMember
Well capitalized requirement, Ratio | 5.00%us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets / dei_LegalEntityAxis = gbci_GlacierBankMember | 5.00%us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets / dei_LegalEntityAxis = gbci_GlacierBankMember

X
- Definition The amount of total capital as defined in the regulations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 948 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6490092&loc=d3e47304-110998 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 948 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=6490092&loc=d3e47080-110998 + Details
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- Definition The minimum amount of Total Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958570-112826 + Details
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- Definition The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition Total Capital divided by risk weighted assets as defined in the regulations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition The minimum amount of Tier 1 Leverage Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition The amount of Tier 1 Leverage Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition Tier 1 Risk Based Capital as defined in the regulations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958570-112826 + Details
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- Definition The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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