$GBCI
GLACIER BANCORP, INC. Stock $gbci

$gbci Overview Financials Valuation SEC Filings Company Website

2019 Q2 Form 10-Q Financial Statement

#000086867119000046 Filed on August 02, 2019

Income Statement

Concept	2019 Q2	2018 Q4	2018 Q2
Revenue	$132.4M	$125.3M	$117.7M
YoY Change	12.46%	29.32%	25.19%
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	$6.300M	$6.300M	$5.500M
YoY Change	14.55%	43.18%	30.95%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$12.09M	$9.436M	$9.161M
YoY Change	31.96%	33.43%	17.84%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$64.96M	$61.25M	$53.87M
YoY Change	20.59%	32.33%	18.15%
Income Tax	$12.57M	$11.65M	$9.485M
% Of Pretax Income	19.35%	19.02%	17.61%
Net Earnings	$52.39M	$49.60M	$44.38M
YoY Change	18.04%	231.63%	31.75%
Net Earnings / Revenue	39.58%	39.58%	37.7%
Basic Earnings Per Share	$0.61	$0.59	$0.53
Diluted Earnings Per Share	$0.61	$0.59	$0.52
COMMON SHARES
Basic Shares Outstanding	85.83M shares	84.52M shares	84.51M shares
Diluted Shares Outstanding	85.86M shares		84.56M shares

Balance Sheet

Concept	2019 Q2	2018 Q4	2018 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments			$3.166B
YoY Change			4.16%
Cash & Equivalents	$231.2M	$203.8M	$368.1M
Short-Term Investments			$2.798B
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$296.9M	$241.5M	$240.4M
YoY Change	23.52%	36.19%	33.67%
Goodwill	$330.9M	$289.6M	$289.5M
YoY Change	14.28%	62.86%	62.83%
Intangibles
YoY Change
Long-Term Investments
YoY Change
Other Assets	$3.000M	$24.00M	$34.00M
YoY Change	-91.18%	-36.84%	-42.37%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$12.68B	$12.12B	$11.90B
YoY Change	6.55%	24.82%	20.18%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$5.000M	$4.000M	$4.000M
YoY Change	25.0%	33.33%	0.0%
Accrued Expenses	$44.00M
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$495.0M	$396.0M	$362.0M
YoY Change	36.74%	9.09%	-19.73%
Long-Term Debt Due	$0.00
YoY Change
Total Short-Term Liabilities	$49.00M	$4.000M	$4.000M
YoY Change	1125.0%	33.33%	0.0%
LONG-TERM LIABILITIES
Long-Term Debt	$155.0M	$149.0M	$144.0M
YoY Change	7.64%	11.19%	9.09%
Other Long-Term Liabilities	$116.0M	$117.0M	$96.00M
YoY Change	20.83%	60.27%	2.13%
Total Long-Term Liabilities	$271.0M	$266.0M	$240.0M
YoY Change	12.92%	28.5%	6.19%
TOTAL LIABILITIES
Total Short-Term Liabilities	$49.00M	$4.000M	$4.000M
Total Long-Term Liabilities	$271.0M	$266.0M	$240.0M
Total Liabilities	$10.99B	$10.60B	$10.42B
YoY Change	5.42%	24.59%	19.96%
SHAREHOLDERS EQUITY
Retained Earnings	$503.8M	$473.2M	$443.7M
YoY Change	13.54%	17.63%	9.08%
Common Stock	$1.139B	$1.051B	$1.050B
YoY Change	8.53%	31.74%	31.76%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$1.687B	$1.516B	$1.474B
YoY Change
Total Liabilities & Shareholders Equity	$12.68B	$12.12B	$11.90B
YoY Change	6.55%	24.82%	20.18%

Cashflow Statement

Concept	2019 Q2	2018 Q4	2018 Q2
OPERATING ACTIVITIES
Net Income	$52.39M	$49.60M	$44.38M
YoY Change	18.04%	231.63%	31.75%
Depreciation, Depletion And Amortization	$6.300M	$6.300M	$5.500M
YoY Change	14.55%	43.18%	30.95%
Cash From Operating Activities	$39.40M	$113.2M	$51.30M
YoY Change	-23.2%	48.56%	19.58%
INVESTING ACTIVITIES
Capital Expenditures	-$8.100M	-$4.600M	-$5.700M
YoY Change	42.11%	91.67%	137.5%
Acquisitions
YoY Change
Other Investing Activities	-$141.3M	-$337.1M	-$320.8M
YoY Change	-55.95%	-37555.56%	-1155.26%
Cash From Investing Activities	-$149.3M	-$341.7M	-$326.5M
YoY Change	-54.27%	22680.0%	-1266.07%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	138.7M	125.2M	192.2M
YoY Change	-27.84%	-231.93%	-385.59%
NET CHANGE
Cash From Operating Activities	39.40M	113.2M	51.30M
Cash From Investing Activities	-149.3M	-341.7M	-326.5M
Cash From Financing Activities	138.7M	125.2M	192.2M
Net Change In Cash	28.80M	-103.3M	-83.00M
YoY Change	-134.7%	411.39%	-2405.56%
FREE CASH FLOW
Cash From Operating Activities	$39.40M	$113.2M	$51.30M
Capital Expenditures	-$8.100M	-$4.600M	-$5.700M
Free Cash Flow	$47.50M	$117.8M	$57.00M
YoY Change	-16.67%	49.87%	25.83%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2019Q2	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	40159000	USD
	dei	Amendment Flag AmendmentFlag	false
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q2
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2019
	dei	Entity Central Index Key EntityCentralIndexKey	0000868671
CY2018	us-gaap	Impairment Of Investments ImpairmentOfInvestments	0	USD
	us-gaap	Impairment Of Investments ImpairmentOfInvestments	0	USD
	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	1	operating_segment
CY2018Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2019Q2	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2018Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	1000000	shares
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2019-06-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity File Number EntityFileNumber	000-18911
	dei	Entity Registrant Name EntityRegistrantName	GLACIER BANCORP INC
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	MT
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	81-0519541
	dei	Entity Address Address Line1 EntityAddressAddressLine1	49 Commons Loop
	dei	Entity Address City Or Town EntityAddressCityOrTown	Kalispell,
	gbci	Fair Value Measurement Transfers From One Level To Another FairValueMeasurementTransfersFromOneLevelToAnother	0	USD
	gbci	Fair Value Measurement Transfers From One Level To Another FairValueMeasurementTransfersFromOneLevelToAnother	0	USD
	us-gaap	Affordable Housing Project Investment Write Down Amount AffordableHousingProjectInvestmentWriteDownAmount	0	USD
	us-gaap	Affordable Housing Project Investment Write Down Amount AffordableHousingProjectInvestmentWriteDownAmount	0	USD
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	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
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	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
	dei	Entity Address State Or Province EntityAddressStateOrProvince	MT
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	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	59901
	dei	City Area Code CityAreaCode	(406)
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	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
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	dei	Local Phone Number LocalPhoneNumber	756-4200
	dei	Document Type DocumentType	10-Q
	dei	Security12b Title Security12bTitle	Common Stock, $0.01 par value
	dei	Trading Symbol TradingSymbol	GBCI
	dei	Security Exchange Name SecurityExchangeName	NASDAQ
	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
	dei	Entity Small Business EntitySmallBusiness	false
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	gbci	Service Chargesand Other Fees ServiceChargesandOtherFees	35675000	USD
CY2019Q2	gbci	Miscellaneous Loan Feesand Charges MiscellaneousLoanFeesandCharges	1192000	USD
CY2018Q2	gbci	Miscellaneous Loan Feesand Charges MiscellaneousLoanFeesandCharges	2243000	USD
	gbci	Miscellaneous Loan Feesand Charges MiscellaneousLoanFeesandCharges	2159000	USD
	gbci	Miscellaneous Loan Feesand Charges MiscellaneousLoanFeesandCharges	3720000	USD
CY2019Q2	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	7762000	USD
CY2018Q2	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	8142000	USD
	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	13560000	USD
	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	14239000	USD
CY2019Q2	us-gaap	Debt Securities Realized Gain Loss DebtSecuritiesRealizedGainLoss	134000	USD
CY2018Q2	us-gaap	Debt Securities Realized Gain Loss DebtSecuritiesRealizedGainLoss	-56000	USD
	us-gaap	Debt Securities Realized Gain Loss DebtSecuritiesRealizedGainLoss	347000	USD
	us-gaap	Debt Securities Realized Gain Loss DebtSecuritiesRealizedGainLoss	-389000	USD
CY2019Q2	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	1721000	USD
CY2018Q2	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	2695000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	5202000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	4669000	USD
CY2019Q2	us-gaap	Noninterest Income NoninterestIncome	30834000	USD
CY2018Q2	us-gaap	Noninterest Income NoninterestIncome	31828000	USD
	us-gaap	Noninterest Income NoninterestIncome	59308000	USD
	us-gaap	Noninterest Income NoninterestIncome	57914000	USD
CY2019Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	51973000	USD
CY2018Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	49023000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	104701000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	94744000	USD
CY2019Q2	us-gaap	Occupancy Net OccupancyNet	8180000	USD
CY2018Q2	us-gaap	Occupancy Net OccupancyNet	7662000	USD
	us-gaap	Occupancy Net OccupancyNet	16617000	USD
	us-gaap	Occupancy Net OccupancyNet	14936000	USD
CY2019Q2	us-gaap	Advertising Expense AdvertisingExpense	2767000	USD
CY2018Q2	us-gaap	Advertising Expense AdvertisingExpense	2530000	USD
	us-gaap	Advertising Expense AdvertisingExpense	5155000	USD
	us-gaap	Advertising Expense AdvertisingExpense	4700000	USD
CY2019Q2	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	4062000	USD
CY2018Q2	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	4241000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	7954000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	8208000	USD
CY2019Q2	us-gaap	Foreclosed Real Estate Expense ForeclosedRealEstateExpense	191000	USD
CY2018Q2	us-gaap	Foreclosed Real Estate Expense ForeclosedRealEstateExpense	211000	USD
	us-gaap	Foreclosed Real Estate Expense ForeclosedRealEstateExpense	330000	USD
	us-gaap	Foreclosed Real Estate Expense ForeclosedRealEstateExpense	283000	USD
CY2019Q2	gbci	General Insuranceand Federal Deposit Insurance Corporation Premium Expense GeneralInsuranceandFederalDepositInsuranceCorporationPremiumExpense	1848000	USD
CY2018Q2	gbci	General Insuranceand Federal Deposit Insurance Corporation Premium Expense GeneralInsuranceandFederalDepositInsuranceCorporationPremiumExpense	1329000	USD
	gbci	General Insuranceand Federal Deposit Insurance Corporation Premium Expense GeneralInsuranceandFederalDepositInsuranceCorporationPremiumExpense	3133000	USD
	gbci	General Insuranceand Federal Deposit Insurance Corporation Premium Expense GeneralInsuranceandFederalDepositInsuranceCorporationPremiumExpense	2535000	USD
CY2019Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1865000	USD
CY2018Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1748000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	3559000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2804000	USD
CY2019Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	15284000	USD
CY2018Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	15051000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	27551000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	27212000	USD
CY2019Q2	us-gaap	Noninterest Expense NoninterestExpense	86170000	USD
CY2018Q2	us-gaap	Noninterest Expense NoninterestExpense	81795000	USD
	us-gaap	Noninterest Expense NoninterestExpense	169000000	USD
	us-gaap	Noninterest Expense NoninterestExpense	155422000	USD
CY2019Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	64960000	USD
CY2018Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	53869000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	125759000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	100825000	USD
CY2019Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	12568000	USD
CY2018Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	9485000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	24235000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	17882000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	52392000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	44384000	USD
	us-gaap	Net Income Loss NetIncomeLoss	101524000	USD
	us-gaap	Net Income Loss NetIncomeLoss	82943000	USD
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.61
CY2018Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.53
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.19
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.00
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.61
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.52
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	6068000	USD
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.19
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.00
CY2019Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.27
CY2018Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.26
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.53
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.49
CY2019Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85826290	shares
CY2018Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	84514257	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85191658	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	82671816	shares
CY2019Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	85858286	shares
CY2018Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	84559268	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	85241238	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	82734407	shares
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	52392000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	44384000	USD
	us-gaap	Net Income Loss NetIncomeLoss	101524000	USD
	us-gaap	Net Income Loss NetIncomeLoss	82943000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	29877000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-6696000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	76329000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-32407000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	134000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-64000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	355000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-346000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	29743000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	-6632000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	75974000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	-32061000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	7537000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-1681000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	19252000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-8125000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	22206000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-4951000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	56722000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-23936000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	-3820000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	1689000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	-278000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	-577000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	-501000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	-1477000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	-5654000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Before Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax	-3542000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Before Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax	2266000	USD
	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Before Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax	-5153000	USD
	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Before Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax	7545000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-897000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	574000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-1306000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	1912000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-2645000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	1692000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-3847000	USD
	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	5633000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	19561000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-3259000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	52875000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-18303000	USD
CY2019Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	71953000	USD
CY2018Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	41125000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	154399000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	64640000	USD
CY2018Q1	us-gaap	Stockholders Equity StockholdersEquity	1454024000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	44384000	USD
CY2018Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-3259000	USD
CY2018Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	22021000	USD
CY2018Q2	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	USD
CY2018Q2	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Restricted Stock Units Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition	864000	USD
CY2018Q2	us-gaap	Stockholders Equity StockholdersEquity	1473992000	USD
CY2019Q1	us-gaap	Stockholders Equity StockholdersEquity	1550850000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	52392000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	19561000	USD
CY2019Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	23437000	USD
CY2019Q2	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	87153000	USD
CY2019Q2	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	USD
CY2019Q2	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Restricted Stock Units Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition	857000	USD
CY2019Q2	us-gaap	Stockholders Equity StockholdersEquity	1687376000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	1199057000	USD
	us-gaap	Net Income Loss NetIncomeLoss	82943000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-18303000	USD
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	41497000	USD
	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	250807000	USD
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	USD
	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Restricted Stock Units Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition	985000	USD
CY2018Q2	us-gaap	Stockholders Equity StockholdersEquity	1473992000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	1515854000	USD
	us-gaap	Net Income Loss NetIncomeLoss	101524000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	52875000	USD
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	45476000	USD
	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	87153000	USD
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	USD
	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Restricted Stock Units Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition	904000	USD
CY2019Q1	us-gaap	Cumulative Effect Of New Accounting Principle In Period Of Adoption CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	-25458000	USD
CY2019Q2	us-gaap	Stockholders Equity StockholdersEquity	1687376000	USD
	us-gaap	Net Income Loss NetIncomeLoss	101524000	USD
	us-gaap	Net Income Loss NetIncomeLoss	82943000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	57000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	5513000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-8707000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-6835000	USD
	gbci	Accretion Amortizationof Discountsand Premiums Business Combinations AccretionAmortizationofDiscountsandPremiumsBusinessCombinations	2187000	USD
	gbci	Accretion Amortizationof Discountsand Premiums Business Combinations AccretionAmortizationofDiscountsandPremiumsBusinessCombinations	1425000	USD
	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	825000	USD
	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	825000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	353921000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	415553000	USD
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	346144000	USD
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	425484000	USD
	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	13560000	USD
	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	14239000	USD
	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	347000	USD
	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	-389000	USD
	us-gaap	Life Insurance Corporate Or Bank Owned Change In Value LifeInsuranceCorporateOrBankOwnedChangeInValue	1021000	USD
	us-gaap	Life Insurance Corporate Or Bank Owned Change In Value LifeInsuranceCorporateOrBankOwnedChangeInValue	1310000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	1850000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	1868000	USD
	us-gaap	Depreciation Nonproduction DepreciationNonproduction	9011000	USD
	us-gaap	Depreciation Nonproduction DepreciationNonproduction	7544000	USD
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	334000	USD
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	81000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	3559000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2804000	USD
	gbci	Variable Interest Entities Investment Amortization VariableInterestEntitiesInvestmentAmortization	3885000	USD
	gbci	Variable Interest Entities Investment Amortization VariableInterestEntitiesInvestmentAmortization	2911000	USD
	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	3213000	USD
	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	4306000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	6520000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-1048000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	749000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	57000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-9518000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-2070000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	85690000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	99237000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	415093000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	219855000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	247854000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	156482000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	457915000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	499552000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	32575000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	26767000	USD
	us-gaap	Proceeds From Loan And Lease Originations And Principal Collections1 ProceedsFromLoanAndLeaseOriginationsAndPrincipalCollections1	1364270000	USD
	us-gaap	Proceeds From Loan And Lease Originations And Principal Collections1 ProceedsFromLoanAndLeaseOriginationsAndPrincipalCollections1	1269145000	USD
	gbci	Payments For Loans Originated Or Acquired PaymentsForLoansOriginatedOrAcquired	1675181000	USD
	gbci	Payments For Loans Originated Or Acquired PaymentsForLoansOriginatedOrAcquired	1681348000	USD
	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	11882000	USD
	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	11297000	USD
	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	2440000	USD
	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	1693000	USD
	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	76948000	USD
	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	41393000	USD
	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	71198000	USD
	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	40385000	USD
	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	0	USD
	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	299000	USD
	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	6451000	USD
	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	23072000	USD
	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	-11307000	USD
	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	-101268000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-72140000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-438752000	USD
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	86429000	USD
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	528881000	USD
	us-gaap	Proceeds From Payments For In Securities Sold Under Agreements To Repurchase ProceedsFromPaymentsForInSecuritiesSoldUnderAgreementsToRepurchase	97091000	USD
	us-gaap	Proceeds From Payments For In Securities Sold Under Agreements To Repurchase ProceedsFromPaymentsForInSecuritiesSoldUnderAgreementsToRepurchase	-30238000	USD
	us-gaap	Proceeds From Repayments Of Short Term Debt Maturing In Three Months Or Less ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess	-120000000	USD
	us-gaap	Proceeds From Repayments Of Short Term Debt Maturing In Three Months Or Less ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess	40000000	USD
	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	987000	USD
	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	528000	USD
	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	54000	USD
	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	-9850000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	1071000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	47560000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	19551000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	13869000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	1158000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	507643000	USD
	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	27419000	USD
	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	168128000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	203790000	USD
CY2017Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	200004000	USD
CY2019Q2	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	231209000	USD
CY2018Q2	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	368132000	USD
	us-gaap	Interest Paid InterestPaid	22244000	USD
	us-gaap	Interest Paid InterestPaid	16878000	USD
	us-gaap	Income Taxes Paid IncomeTaxesPaid	21680000	USD
	us-gaap	Income Taxes Paid IncomeTaxesPaid	12403000	USD
	us-gaap	Transfer Of Other Real Estate TransferOfOtherRealEstate	7000	USD
	us-gaap	Transfer Of Other Real Estate TransferOfOtherRealEstate	372000	USD
	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	1914000	USD
	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	1144000	USD
	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	3862000	USD
	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	0	USD
	gbci	Dividends Declared But Not Paid Duringthe Period DividendsDeclaredButNotPaidDuringthePeriod	23482000	USD
	gbci	Dividends Declared But Not Paid Duringthe Period DividendsDeclaredButNotPaidDuringthePeriod	22211000	USD
	us-gaap	Stock Issued1 StockIssued1	87153000	USD
	us-gaap	Stock Issued1 StockIssued1	250807000	USD
	gbci	Cash Considerationfor Outstanding Shares CashConsiderationforOutstandingShares	4000	USD
	gbci	Cash Considerationfor Outstanding Shares CashConsiderationforOutstandingShares	16265000	USD
	gbci	Business Combination Effective Settlementofa Pre Existing Relationship BusinessCombinationEffectiveSettlementofaPreExistingRelationship	0	USD
	gbci	Business Combination Effective Settlementofa Pre Existing Relationship BusinessCombinationEffectiveSettlementofaPreExistingRelationship	10054000	USD
	us-gaap	Noncash Or Part Noncash Acquisition Value Of Assets Acquired1 NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1	379155000	USD
	us-gaap	Noncash Or Part Noncash Acquisition Value Of Assets Acquired1 NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1	1549158000	USD
	us-gaap	Noncash Or Part Noncash Acquisition Value Of Liabilities Assumed1 NoncashOrPartNoncashAcquisitionValueOfLiabilitiesAssumed1	291998000	USD
	us-gaap	Noncash Or Part Noncash Acquisition Value Of Liabilities Assumed1 NoncashOrPartNoncashAcquisitionValueOfLiabilitiesAssumed1	1383756000	USD
CY2019Q2	gbci	Number Of Bank Divisions NumberOfBankDivisions	15	division
	gbci	Minimum Period Past Dueto Consider Loansas Delinquent MinimumPeriodPastDuetoConsiderLoansasDelinquent	P30D
	gbci	Minimum Period Past Dueto Consider Loansas Non Accrual MinimumPeriodPastDuetoConsiderLoansasNonAccrual	P90D
	gbci	Minimum Period Past Dueto Consider Loansas Non Accrual MinimumPeriodPastDuetoConsiderLoansasNonAccrual	P90D
	gbci	Minimum Period Past Dueto Consider Loansas Non Accrual MinimumPeriodPastDuetoConsiderLoansasNonAccrual	P90D
	gbci	Financing Receivable Allowancefor Credit Losses Numberof Quarters Usedto Evaluate Historical Loss Experience FinancingReceivableAllowanceforCreditLossesNumberofQuartersUsedtoEvaluateHistoricalLossExperience	12	quarter
	gbci	Maximum Term Leases Will Be Considered Shortterm MaximumTermLeasesWillBeConsideredShortterm	P12M
	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	38943000	USD
	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	36553000	USD
CY2019Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	2403517000	USD
CY2019Q2	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	69191000	USD
CY2019Q2	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	2074000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	2470634000	USD
CY2019Q2	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	252097000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	8597000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	0	USD
CY2019Q2	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	260694000	USD
CY2019Q2	gbci	Debt Securities Amortized Cost Basis DebtSecuritiesAmortizedCostBasis	2655614000	USD
CY2019Q2	gbci	Securities Gross Unrealized Gain Accumulatedin Investments SecuritiesGrossUnrealizedGainAccumulatedinInvestments	77788000	USD
CY2019Q2	gbci	Securities Gross Unrealized Loss Accumulatedin Investments1 SecuritiesGrossUnrealizedLossAccumulatedinInvestments1	2074000	USD
CY2019Q2	gbci	Debt Securities Fair Value DebtSecuritiesFairValue	2731328000	USD
CY2018Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	2580520000	USD
CY2018Q4	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	23360000	USD
CY2018Q4	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	32217000	USD
CY2018Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	2571663000	USD
CY2018Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	297915000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	1380000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	11039000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	288256000	USD
CY2018Q4	gbci	Debt Securities Amortized Cost Basis DebtSecuritiesAmortizedCostBasis	2878435000	USD
CY2018Q4	gbci	Securities Gross Unrealized Gain Accumulatedin Investments SecuritiesGrossUnrealizedGainAccumulatedinInvestments	24740000	USD
CY2018Q4	gbci	Securities Gross Unrealized Loss Accumulatedin Investments1 SecuritiesGrossUnrealizedLossAccumulatedinInvestments1	43256000	USD
CY2018Q4	gbci	Debt Securities Fair Value DebtSecuritiesFairValue	2859919000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	50668000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	50748000	USD
CY2019Q2	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	0	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	0	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	241525000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	245014000	USD
CY2019Q2	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	8391000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	8678000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	285233000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	298290000	USD
CY2019Q2	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost	78886000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	82526000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	409614000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	425262000	USD
CY2019Q2	us-gaap	Heldtomaturity Securities Debt Maturities Rolling After Ten Years Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost	164820000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	169490000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	987040000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	1019314000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Amortized Cost Basis HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	252097000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue	260694000	USD
CY2019Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	2403517000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	2470634000	USD
CY2019Q2	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	252097000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	260694000	USD
CY2019Q2	gbci	Proceedsfrom Salesand Callsof Debt Securities Availableforsale ProceedsfromSalesandCallsofDebtSecuritiesAvailableforsale	172323000	USD
CY2018Q2	gbci	Proceedsfrom Salesand Callsof Debt Securities Availableforsale ProceedsfromSalesandCallsofDebtSecuritiesAvailableforsale	4765000	USD
	gbci	Proceedsfrom Salesand Callsof Debt Securities Availableforsale ProceedsfromSalesandCallsofDebtSecuritiesAvailableforsale	476371000	USD
	gbci	Proceedsfrom Salesand Callsof Debt Securities Availableforsale ProceedsfromSalesandCallsofDebtSecuritiesAvailableforsale	233446000	USD
CY2019Q2	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	1347000	USD
CY2018Q2	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	9000	USD
	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	4284000	USD
	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	15000	USD
CY2019Q2	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	1213000	USD
CY2018Q2	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	73000	USD
	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	3929000	USD
	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	361000	USD
CY2019Q2	gbci	Heldto Maturity Securities Gross Realized Gains Losses Sale Proceeds HeldtoMaturitySecuritiesGrossRealizedGainsLossesSaleProceeds	2630000	USD
CY2018Q2	gbci	Heldto Maturity Securities Gross Realized Gains Losses Sale Proceeds HeldtoMaturitySecuritiesGrossRealizedGainsLossesSaleProceeds	13470000	USD
	gbci	Heldto Maturity Securities Gross Realized Gains Losses Sale Proceeds HeldtoMaturitySecuritiesGrossRealizedGainsLossesSaleProceeds	32575000	USD
	gbci	Heldto Maturity Securities Gross Realized Gains Losses Sale Proceeds HeldtoMaturitySecuritiesGrossRealizedGainsLossesSaleProceeds	28935000	USD
CY2019Q2	gbci	Heldto Maturity Securities Sold Security Realized Gain HeldtoMaturitySecuritiesSoldSecurityRealizedGain	0	USD
CY2018Q2	gbci	Heldto Maturity Securities Sold Security Realized Gain HeldtoMaturitySecuritiesSoldSecurityRealizedGain	10000	USD
	gbci	Heldto Maturity Securities Sold Security Realized Gain HeldtoMaturitySecuritiesSoldSecurityRealizedGain	2000	USD
	gbci	Heldto Maturity Securities Sold Security Realized Gain HeldtoMaturitySecuritiesSoldSecurityRealizedGain	64000	USD
CY2019Q2	gbci	Heldto Maturity Securities Sold Security Realized Loss HeldtoMaturitySecuritiesSoldSecurityRealizedLoss	0	USD
CY2018Q2	gbci	Heldto Maturity Securities Sold Security Realized Loss HeldtoMaturitySecuritiesSoldSecurityRealizedLoss	2000	USD
	gbci	Heldto Maturity Securities Sold Security Realized Loss HeldtoMaturitySecuritiesSoldSecurityRealizedLoss	10000	USD
	gbci	Heldto Maturity Securities Sold Security Realized Loss HeldtoMaturitySecuritiesSoldSecurityRealizedLoss	107000	USD
CY2019Q2	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	13372000	USD
CY2019Q2	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	84000	USD
CY2019Q2	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	282981000	USD
CY2019Q2	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	1990000	USD
CY2019Q2	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue	296353000	USD
CY2019Q2	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	2074000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	0	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	0	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	21000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	0	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	21000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	0	USD
CY2018Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	444401000	USD
CY2018Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	3224000	USD
CY2018Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	1016813000	USD
CY2018Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	28993000	USD
CY2018Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue	1461214000	USD
CY2018Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	32217000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	87392000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	2778000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	213618000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	126226000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	8261000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	11039000	USD
	gbci	Financing Receivable Numberof Portfolio Segments FinancingReceivableNumberofPortfolioSegments	3	portfolio_segment
CY2019Q2	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	8841777000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	8287549000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	129054000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	131239000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	8712723000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	8156310000	USD
CY2019Q2	gbci	Unamortized Loan Origination Feesand Costs UnamortizedLoanOriginationFeesandCosts	-5936000	USD
CY2018Q4	gbci	Unamortized Loan Origination Feesand Costs UnamortizedLoanOriginationFeesandCosts	-5685000	USD
CY2019Q2	gbci	Unamortized Discountsand Premiumson Loans UnamortizedDiscountsandPremiumsonLoans	-24349000	USD
CY2018Q4	gbci	Unamortized Discountsand Premiumson Loans UnamortizedDiscountsandPremiumsonLoans	-25172000	USD
	gbci	Weighted Average Interest Rate On Loans WeightedAverageInterestRateOnLoans	0.0519
CY2018	gbci	Weighted Average Interest Rate On Loans WeightedAverageInterestRateOnLoans	0.0497
CY2019Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	129786000	USD
CY2019Q2	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	2859000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	2127000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	129054000	USD
CY2018Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	127608000	USD
CY2018Q2	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	4718000	USD
CY2018Q2	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	2604000	USD
CY2018Q2	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	1842000	USD
CY2018Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	131564000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	131239000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	57000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	6200000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	3958000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	129054000	USD
CY2017Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	129568000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	5513000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	7611000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	4094000	USD
CY2018Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	131564000	USD
CY2019Q2	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	101981000	USD
CY2019Q2	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	8739796000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	8841777000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	108000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	128946000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	129054000	USD
CY2018Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	108788000	USD
CY2018Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	8178761000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	8287549000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	3223000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	128016000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	131239000	USD
CY2019Q2	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	41195000	USD
CY2019Q2	gbci	Financing Receivable Recorded Investment Past Due And Non Accrual Loans FinancingReceivableRecordedInvestmentPastDueAndNonAccrualLoans	82595000	USD
CY2019Q2	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	8759182000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	8841777000	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	47252000	USD
CY2018Q4	gbci	Financing Receivable Recorded Investment Past Due And Non Accrual Loans FinancingReceivableRecordedInvestmentPastDueAndNonAccrualLoans	82837000	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	8204712000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	8287549000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	5638000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	5640000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	108000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	10850000	USD
	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	13632000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	96343000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	113211000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	92346000	USD
	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	91428000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	101981000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	118851000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	108000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	103196000	USD
	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	105060000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	19197000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	19491000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	3223000	USD
CY2018	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	19519000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	89591000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	107486000	USD
CY2018	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	106747000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	108788000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	126977000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	3223000	USD
CY2018	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	126266000	USD
CY2019Q2	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	4	Loan
CY2019Q2	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	388000	USD
CY2019Q2	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	374000	USD
CY2019Q2	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	1	Loan
CY2019Q2	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	305000	USD
CY2018Q2	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	8	Loan
CY2018Q2	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	5273000	USD
CY2018Q2	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	5159000	USD
CY2018Q2	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	Loan
CY2018Q2	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	0	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	8	Loan
	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	2093000	USD
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	2079000	USD
	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	1	Loan
	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	305000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	20	Loan
	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	21270000	USD
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	21156000	USD
	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	1	Loan
	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	334000	USD
CY2019Q2	gbci	Tdr With Pre Modification Loan Balance For Which Oreo Was Received TdrWithPreModificationLoanBalanceForWhichOreoWasReceived	2528000	USD
CY2018Q2	gbci	Tdr With Pre Modification Loan Balance For Which Oreo Was Received TdrWithPreModificationLoanBalanceForWhichOreoWasReceived	1313000	USD
CY2019Q2	us-gaap	Mortgage Loans In Process Of Foreclosure Amount MortgageLoansInProcessOfForeclosureAmount	1437000	USD
CY2018Q4	us-gaap	Mortgage Loans In Process Of Foreclosure Amount MortgageLoansInProcessOfForeclosureAmount	350000	USD
CY2019Q2	gbci	Real Estate Acquired Through Foreclosure Securedby Residential Real Estate RealEstateAcquiredThroughForeclosureSecuredbyResidentialRealEstate	2011000	USD
CY2018Q4	gbci	Real Estate Acquired Through Foreclosure Securedby Residential Real Estate RealEstateAcquiredThroughForeclosureSecuredbyResidentialRealEstate	698000	USD
CY2019Q2	gbci	Finance Lease Right Of Use Asset Gross FinanceLeaseRightOfUseAssetGross	951000	USD
CY2019Q2	gbci	Finance Lease Rightof Use Asset Accumulated Amortization FinanceLeaseRightofUseAssetAccumulatedAmortization	848000	USD
CY2019Q2	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	103000	USD
CY2019Q2	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	41342000	USD
CY2019Q2	us-gaap	Finance Lease Liability FinanceLeaseLiability	142000	USD
CY2019Q2	us-gaap	Operating Lease Liability OperatingLeaseLiability	43596000	USD
CY2019Q2	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P2Y
CY2019Q2	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P19Y
CY2019Q2	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.053
CY2019Q2	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.037
CY2019Q2	us-gaap	Finance Lease Liability Payments Due In Next Rolling Twelve Months FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths	92000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due Next Rolling Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths	3626000	USD
CY2019Q2	us-gaap	Finance Lease Liability Payments Due In Rolling Year Two FinanceLeaseLiabilityPaymentsDueInRollingYearTwo	54000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Two LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo	3527000	USD
CY2019Q2	us-gaap	Finance Lease Liability Payments Due In Rolling Year Three FinanceLeaseLiabilityPaymentsDueInRollingYearThree	1000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Three LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree	3322000	USD
CY2019Q2	us-gaap	Finance Lease Liability Payments Due In Rolling Year Four FinanceLeaseLiabilityPaymentsDueInRollingYearFour	1000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Four LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour	3079000	USD
CY2019Q2	us-gaap	Finance Lease Liability Payments Due In Rolling Year Five FinanceLeaseLiabilityPaymentsDueInRollingYearFive	0	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Five LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive	3018000	USD
CY2019Q2	us-gaap	Finance Lease Liability Payments Due In Rolling After Year Five FinanceLeaseLiabilityPaymentsDueInRollingAfterYearFive	0	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due After Rolling Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive	46619000	USD
CY2019Q2	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	148000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	63191000	USD
CY2019Q2	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	87000	USD
CY2019Q2	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	2073000	USD
CY2019Q2	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	55000	USD
CY2019Q2	us-gaap	Operating Lease Liability OperatingLeaseLiability	43596000	USD
CY2019Q2	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	6000	USD
CY2019Q2	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	41523000	USD
CY2019Q2	us-gaap	Finance Lease Liability FinanceLeaseLiability	142000	USD
CY2019Q2	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	19595000	USD
CY2019Q2	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	16000	USD
	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	32000	USD
CY2019Q2	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	2000	USD
	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	4000	USD
CY2019Q2	us-gaap	Operating Lease Cost OperatingLeaseCost	997000	USD
	us-gaap	Operating Lease Cost OperatingLeaseCost	1910000	USD
CY2019Q2	us-gaap	Short Term Lease Cost ShortTermLeaseCost	119000	USD
	us-gaap	Short Term Lease Cost ShortTermLeaseCost	228000	USD
CY2019Q2	us-gaap	Variable Lease Cost VariableLeaseCost	222000	USD
	us-gaap	Variable Lease Cost VariableLeaseCost	421000	USD
CY2019Q2	us-gaap	Sublease Income SubleaseIncome	1000	USD
	us-gaap	Sublease Income SubleaseIncome	3000	USD
CY2019Q2	us-gaap	Lease Cost LeaseCost	1355000	USD
	us-gaap	Lease Cost LeaseCost	2592000	USD
CY2019Q2	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	2000	USD
CY2019Q2	us-gaap	Operating Lease Payments OperatingLeasePayments	497000	USD
	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	4000	USD
	us-gaap	Operating Lease Payments OperatingLeasePayments	976000	USD
CY2019Q2	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	21000	USD
	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	42000	USD
CY2019Q1	us-gaap	Goodwill Goodwill	289586000	USD
CY2018Q1	us-gaap	Goodwill Goodwill	289535000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	289586000	USD
CY2017Q4	us-gaap	Goodwill Goodwill	177811000	USD
CY2019Q2	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	41301000	USD
CY2018Q2	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	0	USD
	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	41301000	USD
	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	111724000	USD
CY2019Q2	us-gaap	Goodwill Goodwill	330887000	USD
CY2018Q2	us-gaap	Goodwill Goodwill	289535000	USD
CY2019Q2	us-gaap	Goodwill Goodwill	330887000	USD
CY2018Q2	us-gaap	Goodwill Goodwill	289535000	USD
CY2019Q2	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	1478000	USD
CY2018Q2	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	1030000	USD
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	2895000	USD
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	1921000	USD
CY2019Q2	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	2009000	USD
CY2018Q2	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	1423000	USD
	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	3967000	USD
	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	2663000	USD
CY2019Q2	us-gaap	Securities Sold Under Agreements To Repurchase Gross Including Not Subject To Master Netting Arrangement SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	494651000	USD
CY2018Q4	us-gaap	Securities Sold Under Agreements To Repurchase Gross Including Not Subject To Master Netting Arrangement SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	396151000	USD
CY2019Q2	us-gaap	Pledged Financial Instruments Not Separately Reported Securities For Repurchase Agreements PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesForRepurchaseAgreements	635554000	USD
CY2018Q4	us-gaap	Pledged Financial Instruments Not Separately Reported Securities For Repurchase Agreements PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesForRepurchaseAgreements	511294000	USD
CY2019Q2	us-gaap	Securities Sold Under Agreements To Repurchase Gross Including Not Subject To Master Netting Arrangement SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	494651000	USD
CY2018Q4	us-gaap	Securities Sold Under Agreements To Repurchase Gross Including Not Subject To Master Netting Arrangement SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	396151000	USD
CY2019Q2	gbci	Consulting Fees ConsultingFees	2010000	USD
CY2018Q2	gbci	Consulting Fees ConsultingFees	1795000	USD
	gbci	Consulting Fees ConsultingFees	3777000	USD
	gbci	Consulting Fees ConsultingFees	3174000	USD
CY2019Q2	gbci	Debit Card Expense DebitCardExpense	1435000	USD
CY2018Q2	gbci	Debit Card Expense DebitCardExpense	1148000	USD
	gbci	Debit Card Expense DebitCardExpense	3304000	USD
	gbci	Debit Card Expense DebitCardExpense	2788000	USD
CY2019Q2	gbci	Miscellaneous Employee Expenses MiscellaneousEmployeeExpenses	1405000	USD
CY2018Q2	gbci	Miscellaneous Employee Expenses MiscellaneousEmployeeExpenses	1142000	USD
	gbci	Miscellaneous Employee Expenses MiscellaneousEmployeeExpenses	2401000	USD
	gbci	Miscellaneous Employee Expenses MiscellaneousEmployeeExpenses	1933000	USD
CY2019Q2	gbci	Telephone Expenses TelephoneExpenses	1210000	USD
CY2018Q2	gbci	Telephone Expenses TelephoneExpenses	1142000	USD
	gbci	Telephone Expenses TelephoneExpenses	2385000	USD
	gbci	Telephone Expenses TelephoneExpenses	2163000	USD
CY2019Q2	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	1831000	USD
CY2018Q2	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	2926000	USD
	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	2045000	USD
	us-gaap	Business Combination Integration Related Costs BusinessCombinationIntegrationRelatedCosts	4762000	USD
CY2019Q2	us-gaap	Business Development BusinessDevelopment	1123000	USD
CY2018Q2	us-gaap	Business Development BusinessDevelopment	642000	USD
	us-gaap	Business Development BusinessDevelopment	2013000	USD
	us-gaap	Business Development BusinessDevelopment	1110000	USD
CY2019Q2	gbci	Loan Related Expenses LoanRelatedExpenses	943000	USD
CY2018Q2	gbci	Loan Related Expenses LoanRelatedExpenses	984000	USD
	gbci	Loan Related Expenses LoanRelatedExpenses	1802000	USD
	gbci	Loan Related Expenses LoanRelatedExpenses	1788000	USD
CY2019Q2	us-gaap	Postage Expense PostageExpense	823000	USD
CY2018Q2	us-gaap	Postage Expense PostageExpense	776000	USD
	us-gaap	Postage Expense PostageExpense	1656000	USD
	us-gaap	Postage Expense PostageExpense	1555000	USD
CY2019Q2	us-gaap	Supplies Expense SuppliesExpense	786000	USD
CY2018Q2	us-gaap	Supplies Expense SuppliesExpense	792000	USD
	us-gaap	Supplies Expense SuppliesExpense	1511000	USD
	us-gaap	Supplies Expense SuppliesExpense	1483000	USD
CY2019Q2	gbci	Vie Writedowns Lossesand Other Expenses VIEWritedownsLossesandOtherExpenses	906000	USD
CY2018Q2	gbci	Vie Writedowns Lossesand Other Expenses VIEWritedownsLossesandOtherExpenses	938000	USD
	gbci	Vie Writedowns Lossesand Other Expenses VIEWritedownsLossesandOtherExpenses	1451000	USD
	gbci	Vie Writedowns Lossesand Other Expenses VIEWritedownsLossesandOtherExpenses	1412000	USD
CY2019Q2	gbci	Atm Expenses ATMExpenses	519000	USD
CY2018Q2	gbci	Atm Expenses ATMExpenses	345000	USD
	gbci	Atm Expenses ATMExpenses	1013000	USD
	gbci	Atm Expenses ATMExpenses	634000	USD
CY2019Q2	gbci	Deposit Related Expenses DepositRelatedExpenses	630000	USD
CY2018Q2	gbci	Deposit Related Expenses DepositRelatedExpenses	354000	USD
	gbci	Deposit Related Expenses DepositRelatedExpenses	992000	USD
	gbci	Deposit Related Expenses DepositRelatedExpenses	467000	USD
CY2019Q2	gbci	Accounting Fees AccountingFees	472000	USD
CY2018Q2	gbci	Accounting Fees AccountingFees	393000	USD
	gbci	Accounting Fees AccountingFees	925000	USD
	gbci	Accounting Fees AccountingFees	811000	USD
CY2019Q2	us-gaap	Legal Fees LegalFees	281000	USD
CY2018Q2	us-gaap	Legal Fees LegalFees	467000	USD
	us-gaap	Legal Fees LegalFees	588000	USD
	us-gaap	Legal Fees LegalFees	781000	USD
CY2019Q2	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	910000	USD
CY2018Q2	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	1207000	USD
	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	1688000	USD
	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	2351000	USD
CY2019Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	15284000	USD
CY2018Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	15051000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	27551000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	27212000	USD
CY2017Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1979000	USD
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-9427000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-19665000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-1362000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-18303000	USD
CY2018Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-20282000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	52766000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-109000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	52875000	USD
CY2019Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	43448000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	52392000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	44384000	USD
	us-gaap	Net Income Loss NetIncomeLoss	101524000	USD
	us-gaap	Net Income Loss NetIncomeLoss	82943000	USD
CY2019Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85826290	shares
CY2018Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	84514257	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85191658	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	82671816	shares
CY2019Q2	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	31996	shares
CY2018Q2	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	45011	shares
	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	49580	shares
	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	62591	shares
CY2019Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	85858286	shares
CY2018Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	84559268	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	85241238	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	82734407	shares
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.61
CY2018Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.53
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.19
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.00
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.61
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.52
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.19
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.00

Files In Submission

Name	View Source	Status
0000868671-19-000046-index-headers.html	Edgar Link	pending
0000868671-19-000046-index.html	Edgar Link	pending
0000868671-19-000046.txt	Edgar Link	pending
0000868671-19-000046-xbrl.zip	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
gbci-06302019x10q.htm	Edgar Link	pending
gbci-06302019x10q_htm.xml	Edgar Link	completed
gbci-06302019xex311.htm	Edgar Link	pending
gbci-06302019xex312.htm	Edgar Link	pending
gbci-06302019xex32.htm	Edgar Link	pending
gbci-20190630.xsd	Edgar Link	pending
gbci-20190630_cal.xml	Edgar Link	unprocessable
gbci-20190630_def.xml	Edgar Link	unprocessable
gbci-20190630_lab.xml	Edgar Link	unprocessable
gbci-20190630_pre.xml	Edgar Link	unprocessable
MetaLinks.json	Edgar Link	pending
R1.htm	Edgar Link	pending
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report.css	Edgar Link	pending
Show.js	Edgar Link	pending

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$GBCI
GLACIER BANCORP, INC. Stock $gbci

2019 Q2 Form 10-Q Financial Statement

#000086867119000046 Filed on August 02, 2019

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$GBCI GLACIER BANCORP, INC. Stock $gbci

2019 Q2 Form 10-Q Financial Statement

#000086867119000046 Filed on August 02, 2019

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$GBCI
GLACIER BANCORP, INC. Stock $gbci