$COLB
COLUMBIA BANKING SYSTEM, INC. Stock $colb

$colb Overview Financials Valuation SEC Filings Company Website

2021 Q4 Form 10-Q Financial Statement

#000088734321000165 Filed on November 05, 2021

Income Statement

Concept	2021 Q4	2021 Q3	2020 Q3
Revenue		$134.5M	$127.4M
YoY Change		5.62%	-3.89%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development		$8.515M	$7.095M
YoY Change		20.01%	39.06%
% of Gross Profit
Depreciation & Amortization	$11.80M	$4.300M	$4.100M
YoY Change	2850.0%	4.88%	-53.93%
% of Gross Profit
Operating Expenses		$8.515M	$7.095M
YoY Change		20.01%	39.06%
Operating Profit
YoY Change
Interest Expense		$2.000M	$2.658M
YoY Change		-24.76%	-73.64%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$56.00M	$66.49M	$54.68M
YoY Change	-25.41%	21.59%	-13.35%
Income Tax	$13.10M	$13.47M	$9.949M
% Of Pretax Income	23.39%	20.26%	18.19%
Net Earnings	$42.90M	$53.02M	$44.73M
YoY Change	-26.42%	18.52%	-11.81%
Net Earnings / Revenue		39.41%	35.12%
Basic Earnings Per Share		$0.75	$0.63
Diluted Earnings Per Share	$550.0K	$0.74	$0.63
COMMON SHARES
Basic Shares Outstanding	78.52M shares	71.04M shares	70.73M shares
Diluted Shares Outstanding		71.19M shares	70.76M shares

Balance Sheet

Concept	2021 Q4	2021 Q3	2020 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$824.7M	$897.5M	$930.2M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$172.1M	$157.5M	$164.0M
YoY Change	6.22%	-4.0%	-0.84%
Goodwill	$823.2M	$765.8M	$765.8M
YoY Change	7.49%	0.0%	0.0%
Intangibles	$34.65M	$21.12M	$28.75M
YoY Change	29.6%	-26.52%	-24.17%
Long-Term Investments
YoY Change
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$20.95B	$18.60B	$16.23B
YoY Change	26.29%	14.59%	17.99%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$86.00M	$40.00M	$27.00M
YoY Change	16.22%	48.15%	12.5%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$86.00M	$40.00M	$27.00M
YoY Change	16.22%	48.15%	-52.63%
LONG-TERM LIABILITIES
Long-Term Debt	$20.00M	$35.00M	$35.00M
YoY Change	-42.86%	0.0%	0.0%
Other Long-Term Liabilities	$233.0M	$243.0M	$262.0M
YoY Change	-7.17%	-7.25%	100.0%
Total Long-Term Liabilities	$253.0M	$278.0M	$297.0M
YoY Change	-11.54%	-6.4%	78.92%
TOTAL LIABILITIES
Total Short-Term Liabilities	$86.00M	$40.00M	$27.00M
Total Long-Term Liabilities	$253.0M	$278.0M	$297.0M
Total Liabilities	$18.36B	$16.28B	$13.93B
YoY Change	28.93%	16.85%	20.14%
SHAREHOLDERS EQUITY
Retained Earnings	$694.2M	$651.3M	$537.0M
YoY Change	20.68%	21.28%	8.76%
Common Stock	$1.930B	$1.670B	$1.658B
YoY Change	16.21%	0.72%	0.6%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$70.83M	$70.83M	$70.83M
YoY Change	0.0%	0.0%	56.09%
Treasury Stock Shares	2.184M shares	2.184M shares	2.184M shares
Shareholders Equity	$2.589B	$2.323B	$2.302B
YoY Change
Total Liabilities & Shareholders Equity	$20.95B	$18.60B	$16.23B
YoY Change	26.29%	14.59%	17.99%

Cashflow Statement

Concept	2021 Q4	2021 Q3	2020 Q3
OPERATING ACTIVITIES
Net Income	$42.90M	$53.02M	$44.73M
YoY Change	-26.42%	18.52%	-11.81%
Depreciation, Depletion And Amortization	$11.80M	$4.300M	$4.100M
YoY Change	2850.0%	4.88%	-53.93%
Cash From Operating Activities	$46.00M	$61.70M	$60.70M
YoY Change	-5.15%	1.65%	7.82%
INVESTING ACTIVITIES
Capital Expenditures	-$1.800M	-$1.200M	-$3.000M
YoY Change	50.0%	-60.0%	30.43%
Acquisitions
YoY Change
Other Investing Activities	-$423.1M	-$553.0M	-$500.6M
YoY Change	-31.8%	10.47%	-14.7%
Cash From Investing Activities	-$425.0M	-$554.2M	-$503.6M
YoY Change	-31.63%	10.05%	-14.53%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	306.2M	558.5M	275.5M
YoY Change	3.24%	102.72%	-51.9%
NET CHANGE
Cash From Operating Activities	46.00M	61.70M	60.70M
Cash From Investing Activities	-425.0M	-554.2M	-503.6M
Cash From Financing Activities	306.2M	558.5M	275.5M
Net Change In Cash	-72.80M	66.00M	-167.4M
YoY Change	-73.67%	-139.43%	-519.55%
FREE CASH FLOW
Cash From Operating Activities	$46.00M	$61.70M	$60.70M
Capital Expenditures	-$1.800M	-$1.200M	-$3.000M
Free Cash Flow	$47.80M	$62.90M	$63.70M
YoY Change	-3.82%	-1.26%	8.7%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Entity Central Index Key EntityCentralIndexKey	0000887343
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q3
	dei	Amendment Flag AmendmentFlag	false
	dei	Document Type DocumentType	10-Q
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2021-09-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Local Phone Number LocalPhoneNumber	305-1900
	dei	Entity File Number EntityFileNumber	000-20288
	dei	City Area Code CityAreaCode	253
	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2020Q4	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13425000	USD
	dei	Entity Registrant Name EntityRegistrantName	COLUMBIA BANKING SYSTEM, INC.
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	WA
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	91-1422237
	dei	Entity Address Address Line1 EntityAddressAddressLine1	1301 A Street
	dei	Entity Address City Or Town EntityAddressCityOrTown	Tacoma
	dei	Entity Address State Or Province EntityAddressStateOrProvince	WA
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	98402-2156
	dei	Security12b Title Security12bTitle	Common Stock, No Par Value
	dei	Trading Symbol TradingSymbol	COLB
	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
	dei	Entity Small Business EntitySmallBusiness	false
	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
	dei	Entity Shell Company EntityShellCompany	false
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	us-gaap	Noninterest Income NoninterestIncome	69854000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	159865000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	156018000	USD
	us-gaap	Noninterest Income NoninterestIncome	80938000	USD
CY2021Q3	us-gaap	Labor And Related Expense LaborAndRelatedExpense	54679000	USD
CY2020Q3	us-gaap	Labor And Related Expense LaborAndRelatedExpense	55133000	USD
CY2021Q3	us-gaap	Occupancy Net OccupancyNet	9695000	USD
CY2020Q3	us-gaap	Occupancy Net OccupancyNet	8734000	USD
	us-gaap	Occupancy Net OccupancyNet	27739000	USD
	us-gaap	Occupancy Net OccupancyNet	26743000	USD
CY2021Q3	us-gaap	Communications And Information Technology CommunicationsAndInformationTechnology	8515000	USD
CY2020Q3	us-gaap	Communications And Information Technology CommunicationsAndInformationTechnology	7095000	USD
	us-gaap	Communications And Information Technology CommunicationsAndInformationTechnology	24368000	USD
	us-gaap	Communications And Information Technology CommunicationsAndInformationTechnology	22175000	USD
CY2021Q3	us-gaap	Professional Fees ProfessionalFees	4894000	USD
CY2020Q3	us-gaap	Professional Fees ProfessionalFees	3000000	USD
	us-gaap	Professional Fees ProfessionalFees	10973000	USD
	us-gaap	Professional Fees ProfessionalFees	8585000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5611000	USD
CY2021Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1835000	USD
CY2020Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2193000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6713000	USD
CY2021Q3	colb	Taxes Licenses And Fees TaxesLicensesAndFees	1583000	USD
CY2020Q3	colb	Taxes Licenses And Fees TaxesLicensesAndFees	1559000	USD
	colb	Taxes Licenses And Fees TaxesLicensesAndFees	4332000	USD
	colb	Taxes Licenses And Fees TaxesLicensesAndFees	3427000	USD
CY2021Q3	us-gaap	Advertising Expense AdvertisingExpense	678000	USD
CY2020Q3	us-gaap	Advertising Expense AdvertisingExpense	680000	USD
	us-gaap	Advertising Expense AdvertisingExpense	2026000	USD
	us-gaap	Advertising Expense AdvertisingExpense	2822000	USD
CY2021Q3	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	1214000	USD
CY2020Q3	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	826000	USD
	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	3431000	USD
	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	1894000	USD
CY2021Q3	colb	Netcostbenefitofoperationofotherrealestateowned Netcostbenefitofoperationofotherrealestateowned	4000	USD
CY2020Q3	colb	Netcostbenefitofoperationofotherrealestateowned Netcostbenefitofoperationofotherrealestateowned	-160000	USD
	colb	Netcostbenefitofoperationofotherrealestateowned Netcostbenefitofoperationofotherrealestateowned	52000	USD
	colb	Netcostbenefitofoperationofotherrealestateowned Netcostbenefitofoperationofotherrealestateowned	-348000	USD
CY2021Q3	us-gaap	Other Noninterest Expense OtherNoninterestExpense	6910000	USD
CY2020Q3	us-gaap	Other Noninterest Expense OtherNoninterestExpense	6055000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	19285000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	22190000	USD
CY2021Q3	us-gaap	Noninterest Expense NoninterestExpense	90007000	USD
CY2020Q3	us-gaap	Noninterest Expense NoninterestExpense	85115000	USD
	us-gaap	Noninterest Expense NoninterestExpense	257682000	USD
	us-gaap	Noninterest Expense NoninterestExpense	250219000	USD
CY2021Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	66491000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	54683000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	200468000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	117318000	USD
CY2021Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	13474000	USD
CY2020Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	9949000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	40559000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21374000	USD
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	53017000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	44734000	USD
	us-gaap	Net Income Loss NetIncomeLoss	159909000	USD
	us-gaap	Net Income Loss NetIncomeLoss	95944000	USD
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.75
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.63
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.25
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.35
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.74
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.63
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.24
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.35
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	71036000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70726000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70965000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70870000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	71186000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	70762000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	71155000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	70906000	shares
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	53017000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	44734000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	6671000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	436000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-22022000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-1442000	USD
CY2021Q3	us-gaap	Oci Debt Securities Available For Sale Transfer To Held To Maturity Adjustment From Aoci For Amortization Of Gain Loss Tax OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossTax	141000	USD
CY2020Q3	us-gaap	Oci Debt Securities Available For Sale Transfer To Held To Maturity Adjustment From Aoci For Amortization Of Gain Loss Tax OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossTax	0	USD
CY2021Q3	us-gaap	Oci Debt Securities Available For Sale Transfer To Held To Maturity Adjustment From Aoci For Amortization Of Gain Loss After Tax OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossAfterTax	465000	USD
CY2020Q3	us-gaap	Oci Debt Securities Available For Sale Transfer To Held To Maturity Adjustment From Aoci For Amortization Of Gain Loss After Tax OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossAfterTax	0	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-22487000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-1442000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-35000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-24000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	114000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	80000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-114000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-80000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	19000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	-62000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	612000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	621000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	2019000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	2052000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-2019000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-2114000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-24392000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-3476000	USD
CY2021Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	28625000	USD
CY2020Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	41258000	USD
	us-gaap	Net Income Loss NetIncomeLoss	159909000	USD
	us-gaap	Net Income Loss NetIncomeLoss	95944000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	31134000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-36690000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-102777000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	121114000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	73000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	58000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	241000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	191000	USD
	us-gaap	Oci Debt Securities Available For Sale Transfer To Held To Maturity Adjustment From Aoci For Amortization Of Gain Loss Tax OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossTax	246000	USD
	us-gaap	Oci Debt Securities Available For Sale Transfer To Held To Maturity Adjustment From Aoci For Amortization Of Gain Loss Tax OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossTax	0	USD
	us-gaap	Oci Debt Securities Available For Sale Transfer To Held To Maturity Adjustment From Aoci For Amortization Of Gain Loss After Tax OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossAfterTax	810000	USD
	us-gaap	Oci Debt Securities Available For Sale Transfer To Held To Maturity Adjustment From Aoci For Amortization Of Gain Loss After Tax OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossAfterTax	0	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-103828000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	120923000	USD
	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-104000	USD
	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-72000	USD
	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	344000	USD
	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	239000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-344000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-239000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	0	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	-6218000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	0	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	20526000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	1815000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	1349000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	5994000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	4454000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-5994000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	16072000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-109478000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	137234000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	50431000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	233178000	USD
CY2021Q2	us-gaap	Stockholders Equity StockholdersEquity	2333246000	USD
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	53017000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-24392000	USD
CY2021Q3	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	1253000	USD
CY2021Q3	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	3899000	USD
CY2021Q3	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	29000	USD
CY2021Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.58
CY2021Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	43727000	USD
CY2021Q3	us-gaap	Stockholders Equity StockholdersEquity	2323267000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	2347607000	USD
	us-gaap	Net Income Loss NetIncomeLoss	159909000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-109478000	USD
	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	2351000	USD
	colb	Stock Adjustment Value Deferred Compensation StockAdjustmentValueDeferredCompensation	-8000	USD
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	10835000	USD
	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	4100000	USD
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.14
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	83849000	USD
CY2021Q3	us-gaap	Stockholders Equity StockholdersEquity	2323267000	USD
CY2021Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.28
CY2021Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.30
CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	2276755000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	44734000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-3476000	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	1083000	USD
CY2020Q3	colb	Stock Adjustment Deferred Compensation Shares StockAdjustmentDeferredCompensationShares	0	shares
CY2020Q3	colb	Stock Adjustment Value Deferred Compensation StockAdjustmentValueDeferredCompensation	-2000	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	3009000	USD
CY2020Q3	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	16000	USD
CY2020Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.28
CY2020Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	20106000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	2301981000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	2159962000	USD
	us-gaap	Net Income Loss NetIncomeLoss	95944000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	137234000	USD
	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	2028000	USD
	colb	Stock Adjustment Deferred Compensation Shares StockAdjustmentDeferredCompensationShares	0	shares
	colb	Stock Adjustment Value Deferred Compensation StockAdjustmentValueDeferredCompensation	2000	USD
	colb	Stock Adjustment Value Deferred Compensation StockAdjustmentValueDeferredCompensation	2000	USD
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	7918000	USD
	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	2498000	USD
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.06
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	76152000	USD
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	20000000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	2301981000	USD
	us-gaap	Net Income Loss NetIncomeLoss	159909000	USD
	us-gaap	Net Income Loss NetIncomeLoss	95944000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-6300000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	82400000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	10835000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	7918000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	11383000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	14456000	USD
	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	314000	USD
	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	16674000	USD
	us-gaap	Gain Loss On Sale Of Other Assets GainLossOnSaleOfOtherAssets	268000	USD
	us-gaap	Gain Loss On Sale Of Other Assets GainLossOnSaleOfOtherAssets	953000	USD
	colb	Netgainlossonsaleandvaluationadjustmentsof Oreo NetgainlossonsaleandvaluationadjustmentsofOREO	-40000	USD
	colb	Netgainlossonsaleandvaluationadjustmentsof Oreo NetgainlossonsaleandvaluationadjustmentsofOREO	64000	USD
	colb	Gainonbankownedlifeinsurancedeathbenefit Gainonbankownedlifeinsurancedeathbenefit	209000	USD
	colb	Gainonbankownedlifeinsurancedeathbenefit Gainonbankownedlifeinsurancedeathbenefit	0	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	263367000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	356962000	USD
	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	278187000	USD
	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	350273000	USD
	us-gaap	Increase Decrease In Mortgage Loans Held For Sale IncreaseDecreaseInMortgageLoansHeldForSale	-306000	USD
	us-gaap	Increase Decrease In Mortgage Loans Held For Sale IncreaseDecreaseInMortgageLoansHeldForSale	0	USD
	us-gaap	Increase Decrease In Interest And Dividends Receivable IncreaseDecreaseInInterestAndDividendsReceivable	-1945000	USD
	us-gaap	Increase Decrease In Interest And Dividends Receivable IncreaseDecreaseInInterestAndDividendsReceivable	9879000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-52000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-399000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-15761000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	53996000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-18755000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	31703000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	189101000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	143767000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-108551000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	938624000	USD
	colb	Investment In Low Income Housing Tax Credit Partnerships InvestmentInLowIncomeHousingTaxCreditPartnerships	1106000	USD
	colb	Investment In Low Income Housing Tax Credit Partnerships InvestmentInLowIncomeHousingTaxCreditPartnerships	0	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	2408578000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	996951000	USD
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	112372000	USD
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	USD
	us-gaap	Payments To Acquire Loans Receivable PaymentsToAcquireLoansReceivable	176545000	USD
	us-gaap	Payments To Acquire Loans Receivable PaymentsToAcquireLoansReceivable	0	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	4334000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	7538000	USD
	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	1000	USD
	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	53240000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	26914000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	194105000	USD
	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	0	USD
	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	3000000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	586288000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	406767000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	42653000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	0	USD
	us-gaap	Proceeds From Sales Of Assets Investing Activities ProceedsFromSalesOfAssetsInvestingActivities	4287000	USD
	us-gaap	Proceeds From Sales Of Assets Investing Activities ProceedsFromSalesOfAssetsInvestingActivities	2128000	USD
	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	1000	USD
	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	91080000	USD
	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	132000	USD
	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	1034000	USD
	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	671000	USD
	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	1050000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1933439000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1297189000	USD
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	2083537000	USD
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	2915565000	USD
	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	-33819000	USD
	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	-37471000	USD
	us-gaap	Proceeds From Federal Home Loan Bank Advances ProceedsFromFederalHomeLoanBankAdvances	20000	USD
	us-gaap	Proceeds From Federal Home Loan Bank Advances ProceedsFromFederalHomeLoanBankAdvances	1331000000	USD
	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	10000	USD
	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	222010000	USD
	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	0	USD
	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	9222000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	2351000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	2028000	USD
	us-gaap	Payments For Federal Home Loan Bank Advances PaymentsForFederalHomeLoanBankAdvances	20000	USD
	us-gaap	Payments For Federal Home Loan Bank Advances PaymentsForFederalHomeLoanBankAdvances	2277000000	USD
	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	10000	USD
	us-gaap	Repayments Of Other Debt RepaymentsOfOtherDebt	0	USD
	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	222010000	USD
	us-gaap	Repayments Of Other Debt RepaymentsOfOtherDebt	9222000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	59922000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	75630000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	20000000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	4100000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	2498000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	1988047000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	1835994000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	243709000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	682572000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	653766000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	247673000	USD
CY2021Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	897475000	USD
CY2020Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	930245000	USD
	us-gaap	Interest Paid Net InterestPaidNet	6085000	USD
	us-gaap	Interest Paid Net InterestPaidNet	15913000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	45122000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	32745000	USD
	colb	Securities Transfer From Afs To Htm Fair Value SecuritiesTransferFromAFSToHTMFairValue	2012123000	USD
	colb	Securities Transfer From Afs To Htm Fair Value SecuritiesTransferFromAFSToHTMFairValue	0	USD
	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	0	USD
	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	1033000	USD
	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	87000	USD
	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	301000	USD
	colb	Change In Dividends Payable ChangeInDividendsPayable	23927000	USD
	colb	Change In Dividends Payable ChangeInDividendsPayable	522000	USD
CY2021Q3	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	4773742000	USD
CY2021Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	88414000	USD
CY2021Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	30237000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	4831919000	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Amortized Cost After Allowance For Credit Loss DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss	2075158000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	2052000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	6159000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	2071051000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	4997529000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	219873000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	7268000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	5210134000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	0	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	0	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
CY2021Q3	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	0	USD
CY2020Q3	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	0	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	26914000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	194105000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	0	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	0	USD
	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	751000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	435000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	0	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	0	USD
	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	437000	USD
	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	186000	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	0	USD
CY2020Q3	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	0	USD
	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	0	USD
	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	16425000	USD
CY2021Q3	us-gaap	Gain Loss On Investments GainLossOnInvestments	0	USD
CY2020Q3	us-gaap	Gain Loss On Investments GainLossOnInvestments	0	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	314000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	16674000	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	0	USD
CY2020Q3	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	0	USD
	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	0	USD
	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	16425000	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	0	USD
CY2020Q3	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	0	USD
	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	0	USD
	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	3000000	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	0	USD
CY2020Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	0	USD
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	0	USD
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	13425000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	61198000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	61791000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount	0	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	0	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	781405000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	807659000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount	72430000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	72215000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	1526384000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	1559371000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount	1235888000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	1233393000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	2404755000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	2403098000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount	766840000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue	765443000	USD
CY2021Q3	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	4773742000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	4831919000	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Amortized Cost After Allowance For Credit Loss DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss	2075158000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	2071051000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Restricted DebtSecuritiesAvailableForSaleRestricted	844875000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	2332324000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	24252000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	229333000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	5985000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	2561657000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	30237000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	880507000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	6453000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	18597000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	815000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	899104000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	7268000	USD
CY2020Q2	colb	Visa Class Bsharessharessold VisaClassBsharessharessold	17360	shares
CY2021Q3	colb	Visa Class Bsharesremainingshares VisaClassBsharesremainingshares	77683	shares
CY2021Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13400000	USD
CY2021Q3	colb	Minimumloanbalanceofnonaccrualcollateraldependentloansconsideredfor Acl MinimumloanbalanceofnonaccrualcollateraldependentloansconsideredforACL	500000	USD
CY2021Q3	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	9521385000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	9427660000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	142785000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	149140000	USD
CY2021Q3	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	9378600000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	9278520000	USD
CY2021Q3	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	24176000	USD
CY2021Q3	us-gaap	Notes Receivable Gross NotesReceivableGross	9521385000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	34806000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	9427660000	USD
CY2021Q3	colb	Financing Receivable Accrued Interest Reversed Through Interest Income FinancingReceivableAccruedInterestReversedThroughInterestIncome	99000	USD
CY2020Q3	colb	Financing Receivable Accrued Interest Reversed Through Interest Income FinancingReceivableAccruedInterestReversedThroughInterestIncome	393000	USD
	colb	Financing Receivable Accrued Interest Reversed Through Interest Income FinancingReceivableAccruedInterestReversedThroughInterestIncome	532000	USD
	colb	Financing Receivable Accrued Interest Reversed Through Interest Income FinancingReceivableAccruedInterestReversedThroughInterestIncome	1854000	USD
CY2021Q3	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	14097000	USD
CY2020Q4	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	20911000	USD
CY2021Q3	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	1	Modifications
CY2021Q3	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	15000	USD
CY2021Q3	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	15000	USD
CY2020Q3	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	9	Modifications
CY2020Q3	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	4013000	USD
CY2020Q3	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	4013000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	15	Modifications
	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	3383000	USD
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	3383000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	18	Modifications
	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	7066000	USD
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	7066000	USD
CY2021Q3	colb	Financing Receivable Modifications Additional Commitment To Lend FinancingReceivableModificationsAdditionalCommitmentToLend	1300000	USD
CY2020Q4	colb	Financing Receivable Modifications Additional Commitment To Lend FinancingReceivableModificationsAdditionalCommitmentToLend	651000	USD
	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	contract
	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	contract
CY2020Q3	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	contract
CY2021Q3	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	contract
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	colb	Loan Modifications Short Term Deferments Not Classified As Tdr Net Of Unearned Income LoanModificationsShortTermDefermentsNotClassifiedAsTDRNetOfUnearnedIncome	32800000	USD
CY2021Q3	colb	Paycheck Protection Program Pp Ploansnetofunearnedincome PaycheckProtectionProgramPPPloansnetofunearnedincome	337000000	USD
CY2021Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	142988000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	1479000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	1276000	USD
CY2021Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	0	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	142785000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	149140000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	6885000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	6830000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-6300000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	142785000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	151546000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	4582000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	2604000	USD
CY2020Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	7400000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	156968000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	83968000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	17011000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	5979000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	82400000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	156968000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses Period Increase Decrease FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease	-6400000	USD
CY2021Q2	colb	Allowance For Unfunded Loan Commitments And Letters Of Credit AllowanceForUnfundedLoanCommitmentsAndLettersOfCredit	10000000	USD
CY2020Q2	colb	Allowance For Unfunded Loan Commitments And Letters Of Credit AllowanceForUnfundedLoanCommitmentsAndLettersOfCredit	8800000	USD
CY2020Q4	colb	Allowance For Unfunded Loan Commitments And Letters Of Credit AllowanceForUnfundedLoanCommitmentsAndLettersOfCredit	8300000	USD
CY2019Q4	colb	Allowance For Unfunded Loan Commitments And Letters Of Credit AllowanceForUnfundedLoanCommitmentsAndLettersOfCredit	3430000	USD
CY2021Q3	colb	Allowance For Loan And Lease Losses Net Changes In Unfunded Commitments And Letters Of Credit Allowance AllowanceForLoanAndLeaseLossesNetChangesInUnfundedCommitmentsAndLettersOfCreditAllowance	500000	USD
CY2020Q3	colb	Allowance For Loan And Lease Losses Net Changes In Unfunded Commitments And Letters Of Credit Allowance AllowanceForLoanAndLeaseLossesNetChangesInUnfundedCommitmentsAndLettersOfCreditAllowance	800000	USD
	colb	Allowance For Loan And Lease Losses Net Changes In Unfunded Commitments And Letters Of Credit Allowance AllowanceForLoanAndLeaseLossesNetChangesInUnfundedCommitmentsAndLettersOfCreditAllowance	2200000	USD
	colb	Allowance For Loan And Lease Losses Net Changes In Unfunded Commitments And Letters Of Credit Allowance AllowanceForLoanAndLeaseLossesNetChangesInUnfundedCommitmentsAndLettersOfCreditAllowance	4600000	USD
CY2021Q3	colb	Allowance For Unfunded Loan Commitments And Letters Of Credit AllowanceForUnfundedLoanCommitmentsAndLettersOfCredit	10500000	USD
CY2020Q3	colb	Allowance For Unfunded Loan Commitments And Letters Of Credit AllowanceForUnfundedLoanCommitmentsAndLettersOfCredit	9600000	USD
CY2021Q3	colb	Allowance For Unfunded Loan Commitments And Letters Of Credit AllowanceForUnfundedLoanCommitmentsAndLettersOfCredit	10500000	USD
CY2020Q3	colb	Allowance For Unfunded Loan Commitments And Letters Of Credit AllowanceForUnfundedLoanCommitmentsAndLettersOfCredit	9600000	USD
CY2021Q3	us-gaap	Financing Receivable Originated In Current Fiscal Year FinancingReceivableOriginatedInCurrentFiscalYear	2784244000	USD
CY2021Q3	us-gaap	Financing Receivable Originated In Fiscal Year Before Latest Fiscal Year FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear	1228188000	USD
CY2021Q3	us-gaap	Financing Receivable Originated Two Years Before Latest Fiscal Year FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear	1007625000	USD
CY2021Q3	us-gaap	Financing Receivable Originated Three Years Before Latest Fiscal Year FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear	706282000	USD
CY2021Q3	us-gaap	Financing Receivable Originated Four Years Before Latest Fiscal Year FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear	630252000	USD
CY2021Q3	us-gaap	Financing Receivable Originated Five Or More Years Before Latest Fiscal Year FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear	1359472000	USD
CY2021Q3	us-gaap	Financing Receivable Revolving FinancingReceivableRevolving	1770553000	USD
CY2021Q3	colb	Financing Receivable Revolving Convertedto Term Loans FinancingReceivableRevolvingConvertedtoTermLoans	34769000	USD
CY2021Q3	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	9521385000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	142785000	USD
CY2021Q3	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	9378600000	USD
CY2020Q4	us-gaap	Financing Receivable Originated In Current Fiscal Year FinancingReceivableOriginatedInCurrentFiscalYear	2223383000	USD
CY2020Q4	us-gaap	Financing Receivable Originated In Fiscal Year Before Latest Fiscal Year FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear	1379336000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Two Years Before Latest Fiscal Year FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear	985423000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Three Years Before Latest Fiscal Year FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear	875545000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Four Years Before Latest Fiscal Year FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear	812034000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Five Or More Years Before Latest Fiscal Year FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear	1413553000	USD
CY2020Q4	us-gaap	Financing Receivable Revolving FinancingReceivableRevolving	1687345000	USD
CY2020Q4	colb	Financing Receivable Revolving Convertedto Term Loans FinancingReceivableRevolvingConvertedtoTermLoans	51041000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	9427660000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	149140000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	9278520000	USD
CY2021Q2	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	381000	USD
CY2020Q2	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	747000	USD
CY2020Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	553000	USD
CY2019Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	552000	USD
CY2021Q3	colb	Real Estate Acquired Through Foreclosure Transfers In Net Of Write Downs RealEstateAcquiredThroughForeclosureTransfersInNetOfWriteDowns	0	USD
CY2020Q3	colb	Real Estate Acquired Through Foreclosure Transfers In Net Of Write Downs RealEstateAcquiredThroughForeclosureTransfersInNetOfWriteDowns	475000	USD
	colb	Real Estate Acquired Through Foreclosure Transfers In Net Of Write Downs RealEstateAcquiredThroughForeclosureTransfersInNetOfWriteDowns	0	USD
	colb	Real Estate Acquired Through Foreclosure Transfers In Net Of Write Downs RealEstateAcquiredThroughForeclosureTransfersInNetOfWriteDowns	1033000	USD
CY2021Q3	colb	Transfer Other Real Estate Write Down TransferOtherRealEstateWriteDown	0	USD
CY2020Q3	colb	Transfer Other Real Estate Write Down TransferOtherRealEstateWriteDown	0	USD
	colb	Transfer Other Real Estate Write Down TransferOtherRealEstateWriteDown	140000	USD
	colb	Transfer Other Real Estate Write Down TransferOtherRealEstateWriteDown	0	USD
CY2021Q3	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	0	USD
CY2020Q3	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	681000	USD
	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	132000	USD
	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	1026000	USD
CY2021Q3	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	0	USD
CY2020Q3	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	82000	USD
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	100000	USD
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	64000	USD
CY2021Q3	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	381000	USD
CY2020Q3	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	623000	USD
CY2021Q3	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	381000	USD
CY2020Q3	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	623000	USD
CY2021Q3	us-gaap	Mortgage Loans In Process Of Foreclosure Amount MortgageLoansInProcessOfForeclosureAmount	0	USD
CY2021Q3	us-gaap	Goodwill Goodwill	765842000	USD
CY2020Q3	us-gaap	Goodwill Goodwill	765842000	USD
CY2021Q3	us-gaap	Goodwill Goodwill	765842000	USD
CY2021Q3	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	919000	USD
CY2020Q3	us-gaap	Goodwill Goodwill	765842000	USD
CY2021Q3	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	919000	USD
CY2020Q3	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	919000	USD
CY2020Q3	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	919000	USD
CY2021Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	21123000	USD
CY2020Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	28745000	USD
CY2021Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	21123000	USD
CY2020Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	28745000	USD
CY2021Q3	colb	Goodwill And Intangible Assets Total GoodwillAndIntangibleAssetsTotal	786965000	USD
CY2020Q3	colb	Goodwill And Intangible Assets Total GoodwillAndIntangibleAssetsTotal	794587000	USD
CY2021Q3	colb	Goodwill And Intangible Assets Total GoodwillAndIntangibleAssetsTotal	786965000	USD
CY2020Q3	colb	Goodwill And Intangible Assets Total GoodwillAndIntangibleAssetsTotal	794587000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	1653000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	5880000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	4552000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	3432000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	2415000	USD
CY2021Q3	us-gaap	Line Of Credit Facility Maximum Borrowing Capacity LineOfCreditFacilityMaximumBorrowingCapacity	15000000	USD
CY2021Q3	us-gaap	Interest Rate Cash Flow Hedge Gain Loss To Be Reclassified During Next12 Months Net InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet	10400000	USD
CY2021Q3	us-gaap	Unrealized Gain Loss On Interest Rate Cash Flow Hedges Pretax Accumulated Other Comprehensive Income Loss UnrealizedGainLossOnInterestRateCashFlowHedgesPretaxAccumulatedOtherComprehensiveIncomeLoss	0	USD
CY2020Q3	us-gaap	Unrealized Gain Loss On Interest Rate Cash Flow Hedges Pretax Accumulated Other Comprehensive Income Loss UnrealizedGainLossOnInterestRateCashFlowHedgesPretaxAccumulatedOtherComprehensiveIncomeLoss	-81000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	2631000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	2673000	USD
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CY2021Q3	colb	Repurchaseagreementsamountsoffsetinbalancesheet Repurchaseagreementsamountsoffsetinbalancesheet	0	USD
CY2021Q3	colb	Repurchaseagreementsnetamountpresentedinstatementoffinancialposition Repurchaseagreementsnetamountpresentedinstatementoffinancialposition	40040000	USD
CY2021Q3	us-gaap	Securities Sold Under Agreements To Repurchase Collateral Right To Reclaim Securities SecuritiesSoldUnderAgreementsToRepurchaseCollateralRightToReclaimSecurities	40040000	USD
CY2021Q3	colb	Securitiessoldunderagreementstorepurchaseamountnotoffset Securitiessoldunderagreementstorepurchaseamountnotoffset	0	USD
CY2020Q4	colb	Repurchaseagreementsamountsoffsetinbalancesheet Repurchaseagreementsamountsoffsetinbalancesheet	0	USD
CY2020Q4	colb	Repurchaseagreementsnetamountpresentedinstatementoffinancialposition Repurchaseagreementsnetamountpresentedinstatementoffinancialposition	73859000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase Collateral Right To Reclaim Securities SecuritiesSoldUnderAgreementsToRepurchaseCollateralRightToReclaimSecurities	73859000	USD
CY2020Q4	colb	Securitiessoldunderagreementstorepurchaseamountnotoffset Securitiessoldunderagreementstorepurchaseamountnotoffset	0	USD
CY2021Q3	us-gaap	Secured Borrowings Gross Including Not Subject To Master Netting Arrangement SecuredBorrowingsGrossIncludingNotSubjectToMasterNettingArrangement	40040000	USD
CY2021Q3	us-gaap	Secured Borrowings Gross Difference Amount SecuredBorrowingsGrossDifferenceAmount	0	USD
CY2021Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.28
CY2021Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.28
CY2021Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.28
CY2021Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.30
CY2021Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	97109000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-22022000	USD
CY2021Q3	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	2370000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-24392000	USD
CY2021Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	72717000	USD
CY2020Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	181077000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-1504000	USD
CY2020Q3	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	1972000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-3476000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	177601000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	182195000	USD
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CY2021Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	72717000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	40367000	USD
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	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	137234000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	177601000	USD
CY2021Q3	colb	Visa Class Bsharesremainingshares VisaClassBsharesremainingshares	77683	shares
CY2021Q2	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13425000	USD
CY2020Q2	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13425000	USD
CY2020Q4	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13425000	USD
CY2019Q4	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	0	USD
CY2021Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Upward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount	0	USD
CY2020Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Upward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount	0	USD
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CY2021Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13425000	USD
CY2020Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13425000	USD
CY2021Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13425000	USD
CY2020Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13425000	USD
CY2021Q3	colb	Fair Value Loans Held For Sale Mandatory Delivery Method Fv Option FairValueLoansHeldForSaleMandatoryDeliveryMethodFVOption	10847000	USD
CY2021Q3	colb	Fair Value Fv Option Aggregate Unpaid Balance Loans And Long Term Receivables FairValueFVOptionAggregateUnpaidBalanceLoansAndLongTermReceivables	10645000	USD
CY2021Q3	us-gaap	Fair Value Option Aggregate Differences Loans And Long Term Receivables FairValueOptionAggregateDifferencesLoansAndLongTermReceivables	202000	USD
CY2020Q3	colb	Fair Value Loans Held For Sale Mandatory Delivery Method Fv Option FairValueLoansHeldForSaleMandatoryDeliveryMethodFVOption	14760000	USD
CY2020Q3	colb	Fair Value Fv Option Aggregate Unpaid Balance Loans And Long Term Receivables FairValueFVOptionAggregateUnpaidBalanceLoansAndLongTermReceivables	14252000	USD
CY2020Q3	us-gaap	Fair Value Option Aggregate Differences Loans And Long Term Receivables FairValueOptionAggregateDifferencesLoansAndLongTermReceivables	508000	USD
CY2021Q3	us-gaap	Fair Value Option Changes In Fair Value Gain Loss1 FairValueOptionChangesInFairValueGainLoss1	-161000	USD
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CY2020Q3	us-gaap	Fair Value Option Changes In Fair Value Gain Loss1 FairValueOptionChangesInFairValueGainLoss1	0	USD
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	53017000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	44734000	USD
	us-gaap	Net Income Loss NetIncomeLoss	159909000	USD
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CY2021Q3	colb	Earningsallocatedtoparticipatingsecuritiesnonvestedrestrictedshares Earningsallocatedtoparticipatingsecuritiesnonvestedrestrictedshares	91000	USD
CY2020Q3	colb	Earningsallocatedtoparticipatingsecuritiesnonvestedrestrictedshares Earningsallocatedtoparticipatingsecuritiesnonvestedrestrictedshares	164000	USD
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CY2021Q3	colb	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	52926000	USD
CY2020Q3	colb	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	44570000	USD
	colb	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	159592000	USD
	colb	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	95457000	USD
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	71036000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70726000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70965000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70870000	shares
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.75
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.63
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.25
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.35
CY2021Q3	colb	Diluted Earnings Allocated To Common Shareholders DilutedEarningsAllocatedToCommonShareholders	52926000	USD
CY2020Q3	colb	Diluted Earnings Allocated To Common Shareholders DilutedEarningsAllocatedToCommonShareholders	44570000	USD
	colb	Diluted Earnings Allocated To Common Shareholders DilutedEarningsAllocatedToCommonShareholders	159592000	USD
	colb	Diluted Earnings Allocated To Common Shareholders DilutedEarningsAllocatedToCommonShareholders	95457000	USD
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	71036000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70726000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70965000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70870000	shares
CY2021Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	150000	shares
CY2020Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	36000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	190000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	36000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	71186000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	70762000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	71155000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	70906000	shares
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.74
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.63
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.24
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.35
CY2021Q3	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	269000	shares
CY2020Q3	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	596000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	198000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	487000	shares
CY2021Q3	colb	Depositaccountandtreasurymanagementfees Depositaccountandtreasurymanagementfees	6893000	USD
CY2020Q3	colb	Depositaccountandtreasurymanagementfees Depositaccountandtreasurymanagementfees	6658000	USD
	colb	Depositaccountandtreasurymanagementfees Depositaccountandtreasurymanagementfees	19952000	USD
	colb	Depositaccountandtreasurymanagementfees Depositaccountandtreasurymanagementfees	20538000	USD
CY2021Q3	colb	Cardrevenue Cardrevenue	4889000	USD
CY2020Q3	colb	Cardrevenue Cardrevenue	3834000	USD
	colb	Cardrevenue Cardrevenue	13395000	USD
	colb	Cardrevenue Cardrevenue	10431000	USD
CY2021Q3	colb	Financialservicesandtrustrevenue Financialservicesandtrustrevenue	4250000	USD
CY2020Q3	colb	Financialservicesandtrustrevenue Financialservicesandtrustrevenue	3253000	USD
	colb	Financialservicesandtrustrevenue Financialservicesandtrustrevenue	11876000	USD
	colb	Financialservicesandtrustrevenue Financialservicesandtrustrevenue	9481000	USD
CY2021Q3	colb	Revenuefromcontractswithcustomers Revenuefromcontractswithcustomers	16032000	USD
CY2020Q3	colb	Revenuefromcontractswithcustomers Revenuefromcontractswithcustomers	13745000	USD
	colb	Revenuefromcontractswithcustomers Revenuefromcontractswithcustomers	45223000	USD
	colb	Revenuefromcontractswithcustomers Revenuefromcontractswithcustomers	40450000	USD
CY2021Q3	colb	Noninterestincomeexcludingrevenuefromcontractswithcustomers Noninterestincomeexcludingrevenuefromcontractswithcustomers	7926000	USD
CY2020Q3	colb	Noninterestincomeexcludingrevenuefromcontractswithcustomers Noninterestincomeexcludingrevenuefromcontractswithcustomers	8727000	USD
	colb	Noninterestincomeexcludingrevenuefromcontractswithcustomers Noninterestincomeexcludingrevenuefromcontractswithcustomers	24631000	USD
	colb	Noninterestincomeexcludingrevenuefromcontractswithcustomers Noninterestincomeexcludingrevenuefromcontractswithcustomers	40488000	USD
CY2021Q3	us-gaap	Noninterest Income NoninterestIncome	23958000	USD
CY2020Q3	us-gaap	Noninterest Income NoninterestIncome	22472000	USD
	us-gaap	Noninterest Income NoninterestIncome	69854000	USD
	us-gaap	Noninterest Income NoninterestIncome	80938000	USD

Files In Submission

Name	View Source	Status
0000887343-21-000165-index-headers.html	Edgar Link	pending
0000887343-21-000165-index.html	Edgar Link	pending
0000887343-21-000165.txt	Edgar Link	pending
0000887343-21-000165-xbrl.zip	Edgar Link	pending
colb-20210930.htm	Edgar Link	pending
colb-20210930.xsd	Edgar Link	pending
colb-20210930_cal.xml	Edgar Link	unprocessable
colb-20210930_def.xml	Edgar Link	unprocessable
colb-20210930_htm.xml	Edgar Link	completed
colb-20210930_lab.xml	Edgar Link	unprocessable
colb-20210930_pre.xml	Edgar Link	unprocessable
colb3q2021ex311.htm	Edgar Link	pending
colb3q2021ex312.htm	Edgar Link	pending
colb3q2021ex32.htm	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
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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$COLB
COLUMBIA BANKING SYSTEM, INC. Stock $colb

2021 Q4 Form 10-Q Financial Statement

#000088734321000165 Filed on November 05, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$COLB COLUMBIA BANKING SYSTEM, INC. Stock $colb

2021 Q4 Form 10-Q Financial Statement

#000088734321000165 Filed on November 05, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$COLB
COLUMBIA BANKING SYSTEM, INC. Stock $colb