$COLB
COLUMBIA BANKING SYSTEM, INC. Stock $colb

$colb Overview Financials Valuation SEC Filings Company Website

2021 Q3 Form 10-K Financial Statement

#000088734322000038 Filed on February 25, 2022

Income Statement

Concept	2021 Q3	2021 Q2	2021 Q1
Revenue	$134.5M	$127.4M	$126.0M
YoY Change	5.62%	0.96%	-3.71%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development	$8.515M	$7.402M	$8.451M
YoY Change	20.01%	-7.25%	19.04%
% of Gross Profit
Depreciation & Amortization	$4.300M	$5.700M	$1.400M
YoY Change	4.88%	-303.57%	-89.39%
% of Gross Profit
Operating Expenses	$8.515M	$7.402M	$8.451M
YoY Change	20.01%	-7.25%	19.04%
Operating Profit
YoY Change
Interest Expense	$2.000M	$1.985M	$2.048M
YoY Change	-24.76%	-54.69%	-75.83%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$66.49M	$69.58M	$64.40M
YoY Change	21.59%	55.38%	260.63%
Income Tax	$13.47M	$14.54M	$12.55M
% Of Pretax Income	20.26%	20.89%	19.48%
Net Earnings	$53.02M	$55.04M	$51.85M
YoY Change	18.52%	50.45%	254.48%
Net Earnings / Revenue	39.41%	43.19%	41.14%
Basic Earnings Per Share	$0.75	$0.77	$0.73
Diluted Earnings Per Share	$0.74	$0.77	$0.73
COMMON SHARES
Basic Shares Outstanding	71.04M shares	70.99M shares	70.87M shares
Diluted Shares Outstanding	71.19M shares	71.16M shares	71.11M shares

Balance Sheet

Concept	2021 Q3	2021 Q2	2021 Q1
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$897.5M	$831.5M	$884.5M
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	$157.5M	$158.8M	$160.2M
YoY Change	-4.0%	-3.37%	-2.7%
Goodwill	$765.8M	$765.8M	$765.8M
YoY Change	0.0%	0.0%	0.0%
Intangibles	$21.12M	$22.96M	$24.81M
YoY Change	-26.52%	-25.79%	-25.15%
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	$18.60B	$18.01B	$17.34B
YoY Change	14.59%	13.14%	23.48%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$40.00M	$71.00M	$39.00M
YoY Change	48.15%	39.22%	14.71%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$40.00M	$71.00M	$39.00M
YoY Change	48.15%	39.22%	14.71%
LONG-TERM LIABILITIES
Long-Term Debt	$35.00M	$35.00M	$35.00M
YoY Change	0.0%	0.0%	0.0%
Other Long-Term Liabilities	$243.0M	$221.0M	$212.0M
YoY Change	-7.25%	-17.84%	-7.83%
Total Long-Term Liabilities	$278.0M	$256.0M	$247.0M
YoY Change	-6.4%	-15.79%	-6.79%
TOTAL LIABILITIES
Total Short-Term Liabilities	$40.00M	$71.00M	$39.00M
Total Long-Term Liabilities	$278.0M	$256.0M	$247.0M
Total Liabilities	$16.28B	$15.68B	$15.06B
YoY Change	16.85%	14.92%	27.36%
SHAREHOLDERS EQUITY
Retained Earnings	$651.3M	$642.0M	$607.0M
YoY Change	21.28%	25.3%	22.43%
Common Stock	$1.670B	$1.665B	$1.661B
YoY Change	0.72%	0.65%	0.59%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$70.83M	$70.83M	$70.83M
YoY Change	0.0%	0.0%	0.0%
Treasury Stock Shares	2.184M shares	2.184M shares	2.184M shares
Shareholders Equity	$2.323B	$2.333B	$2.275B
YoY Change
Total Liabilities & Shareholders Equity	$18.60B	$18.01B	$17.34B
YoY Change	14.59%	13.14%	23.48%

Cashflow Statement

Concept	2021 Q3	2021 Q2	2021 Q1
OPERATING ACTIVITIES
Net Income	$53.02M	$55.04M	$51.85M
YoY Change	18.52%	50.45%	254.48%
Depreciation, Depletion And Amortization	$4.300M	$5.700M	$1.400M
YoY Change	4.88%	-303.57%	-89.39%
Cash From Operating Activities	$61.70M	$68.30M	$59.07M
YoY Change	1.65%	285.88%	-9.63%
INVESTING ACTIVITIES
Capital Expenditures	-$1.200M	-$2.300M	$805.0K
YoY Change	-60.0%	-17.86%	-51.21%
Acquisitions
YoY Change
Other Investing Activities	-$553.0M	-$709.2M	-$666.9M
YoY Change	10.47%	-20.67%	-735.75%
Cash From Investing Activities	-$554.2M	-$711.5M	-$667.7M
YoY Change	10.05%	-20.66%	-746.8%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net			$0.00
YoY Change			-100.0%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	558.5M	590.1M	$839.4M
YoY Change	102.72%	-66.49%	-518.6%
NET CHANGE
Cash From Operating Activities	61.70M	68.30M	$59.07M
Cash From Investing Activities	-554.2M	-711.5M	-$667.7M
Cash From Financing Activities	558.5M	590.1M	$839.4M
Net Change In Cash	66.00M	-53.10M	$230.7M
YoY Change	-139.43%	-106.02%	-822.87%
FREE CASH FLOW
Cash From Operating Activities	$61.70M	$68.30M	$59.07M
Capital Expenditures	-$1.200M	-$2.300M	$805.0K
Free Cash Flow	$62.90M	$70.60M	$58.27M
YoY Change	-1.26%	244.39%	-8.55%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2021	dei	Entity Central Index Key EntityCentralIndexKey	0000887343
CY2021	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
CY2021	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2021	dei	Amendment Flag AmendmentFlag	false
CY2021	dei	Document Type DocumentType	10-K
CY2021	dei	Document Annual Report DocumentAnnualReport	true
CY2021	dei	Document Period End Date DocumentPeriodEndDate	2021-12-31
CY2021	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2021	dei	Document Transition Report DocumentTransitionReport	false
CY2021	dei	Entity File Number EntityFileNumber	000-20288
CY2021	dei	Entity Registrant Name EntityRegistrantName	COLUMBIA BANKING SYSTEM, INC.
CY2021	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	WA
CY2021	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	91-1422237
CY2021	dei	Entity Address Address Line1 EntityAddressAddressLine1	1301 A Street
CY2021	dei	Entity Address City Or Town EntityAddressCityOrTown	Tacoma
CY2021	dei	Entity Address State Or Province EntityAddressStateOrProvince	WA
CY2021	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	98402-2156
CY2021	dei	City Area Code CityAreaCode	253
CY2021	dei	Local Phone Number LocalPhoneNumber	305-1900
CY2021	dei	Security12b Title Security12bTitle	Common Stock, No Par Value
CY2021	dei	Trading Symbol TradingSymbol	COLB
CY2021	dei	Security Exchange Name SecurityExchangeName	NASDAQ
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CY2021	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
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CY2021	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
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CY2021	us-gaap	Professional Fees ProfessionalFees	18910000	USD
CY2020	us-gaap	Professional Fees ProfessionalFees	12158000	USD
CY2019	us-gaap	Professional Fees ProfessionalFees	21645000	USD
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	7987000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	8724000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	10479000	USD
CY2021	colb	Businessand Occupationtaxes BusinessandOccupationtaxes	5903000	USD
CY2020	colb	Businessand Occupationtaxes BusinessandOccupationtaxes	4970000	USD
CY2019	colb	Businessand Occupationtaxes BusinessandOccupationtaxes	5846000	USD
CY2021	us-gaap	Advertising Expense AdvertisingExpense	3383000	USD
CY2020	us-gaap	Advertising Expense AdvertisingExpense	4466000	USD
CY2019	us-gaap	Advertising Expense AdvertisingExpense	4925000	USD
CY2021	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	4912000	USD
CY2020	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	2956000	USD
CY2019	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	1920000	USD
CY2021	colb	Netcostbenefitofoperationofotherrealestateowned Netcostbenefitofoperationofotherrealestateowned	66000	USD
CY2020	colb	Netcostbenefitofoperationofotherrealestateowned Netcostbenefitofoperationofotherrealestateowned	-315000	USD
CY2019	colb	Netcostbenefitofoperationofotherrealestateowned Netcostbenefitofoperationofotherrealestateowned	-692000	USD
CY2021	us-gaap	Other Noninterest Expense OtherNoninterestExpense	23796000	USD
CY2020	us-gaap	Other Noninterest Expense OtherNoninterestExpense	26376000	USD
CY2019	us-gaap	Other Noninterest Expense OtherNoninterestExpense	26221000	USD
CY2021	us-gaap	Noninterest Expense NoninterestExpense	360304000	USD
CY2020	us-gaap	Noninterest Expense NoninterestExpense	334519000	USD
CY2019	us-gaap	Noninterest Expense NoninterestExpense	345482000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	256509000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	192392000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	241611000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	53689000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	38148000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	47160000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	202820000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	154244000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	194451000	USD
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.79
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.17
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.68
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.78
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.17
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.68
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	72683000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70835000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	71999000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	72873000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	70880000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	72032000	shares
CY2021	us-gaap	Net Income Loss NetIncomeLoss	202820000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	154244000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	194451000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	41647000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-39489000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-20540000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-137482000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	130355000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	67802000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	73000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	66000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	496000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	242000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	219000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	1636000	USD
CY2021	us-gaap	Oci Debt Securities Available For Sale Transfer To Held To Maturity Adjustment From Aoci For Amortization Of Gain Loss Tax OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossTax	702000	USD
CY2020	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
CY2019	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
CY2021	us-gaap	Oci Debt Securities Available For Sale Transfer To Held To Maturity Adjustment From Aoci For Amortization Of Gain Loss After Tax OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossAfterTax	2316000	USD
CY2020	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
CY2019	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
CY2021	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-140040000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	130136000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	66166000	USD
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-170000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	659000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	619000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Reclassification Adjustments Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsNetOfTax	-562000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Reclassification Adjustments Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsNetOfTax	2177000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Reclassification Adjustments Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsNetOfTax	2042000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-139000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-96000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-74000	USD
CY2021	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	459000	USD
CY2020	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	318000	USD
CY2019	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	245000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-1021000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	1859000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	1797000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	-6062000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	-3562000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	20012000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	11760000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	2427000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	1957000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	138000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	8014000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	6461000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	457000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-8014000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	13551000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	11303000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-147033000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	141828000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	75672000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	55787000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	296072000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	270123000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	2033649000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	194451000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	75672000	USD
CY2019	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	2025000	USD
CY2019	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	9271000	USD
CY2019	colb	Stock Adjustment Value Deferred Compensation StockAdjustmentValueDeferredCompensation	3000	USD
CY2019	colb	Stock Adjustment Value Deferred Compensation StockAdjustmentValueDeferredCompensation	3000	USD
CY2019	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	2792000	USD
CY2019	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.40
CY2019	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	102265000	USD
CY2019	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	50834000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	2159962000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	154244000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	141828000	USD
CY2020	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	2028000	USD
CY2020	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	10737000	USD
CY2020	colb	Stock Adjustment Value Deferred Compensation StockAdjustmentValueDeferredCompensation	2000	USD
CY2020	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	2522000	USD
CY2020	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.34
CY2020	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	96215000	USD
CY2020	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	20000000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	2347607000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	202820000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-147033000	USD
CY2021	us-gaap	Stock Issued During Period Shares Acquisitions StockIssuedDuringPeriodSharesAcquisitions	6740000	shares
CY2021	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	256061000	USD
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	2350000	USD
CY2021	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	14926000	USD
CY2021	colb	Stock Adjustment Value Deferred Compensation StockAdjustmentValueDeferredCompensation	-8000	USD
CY2021	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	4140000	USD
CY2021	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.14
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	83841000	USD
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	2588742000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	202820000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	154244000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	194451000	USD
CY2021	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	4800000	USD
CY2020	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	77700000	USD
CY2019	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	3493000	USD
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	14926000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	10737000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	9271000	USD
CY2021	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	23168000	USD
CY2020	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	14893000	USD
CY2019	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	34213000	USD
CY2021	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	314000	USD
CY2020	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	16710000	USD
CY2019	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	2132000	USD
CY2021	us-gaap	Gain Loss On Sale Of Other Assets GainLossOnSaleOfOtherAssets	500000	USD
CY2020	us-gaap	Gain Loss On Sale Of Other Assets GainLossOnSaleOfOtherAssets	1334000	USD
CY2019	us-gaap	Gain Loss On Sale Of Other Assets GainLossOnSaleOfOtherAssets	7317000	USD
CY2021	colb	Netgainonsaleandvaluationadjustmentsof Oreo NetgainonsaleandvaluationadjustmentsofOREO	-40000	USD
CY2020	colb	Netgainonsaleandvaluationadjustmentsof Oreo NetgainonsaleandvaluationadjustmentsofOREO	34000	USD
CY2019	colb	Netgainonsaleandvaluationadjustmentsof Oreo NetgainonsaleandvaluationadjustmentsofOREO	602000	USD
CY2021	us-gaap	Gain Loss On Sale Of Insurance Block GainLossOnSaleOfInsuranceBlock	344000	USD
CY2020	us-gaap	Gain Loss On Sale Of Insurance Block GainLossOnSaleOfInsuranceBlock	0	USD
CY2019	us-gaap	Gain Loss On Sale Of Insurance Block GainLossOnSaleOfInsuranceBlock	3051000	USD
CY2021	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	336455000	USD
CY2020	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	491385000	USD
CY2019	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	210484000	USD
CY2021	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	352823000	USD
CY2020	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	483130000	USD
CY2019	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	196615000	USD
CY2021	us-gaap	Increase Decrease In Mortgage Loans Held For Sale IncreaseDecreaseInMortgageLoansHeldForSale	-339000	USD
CY2020	us-gaap	Increase Decrease In Mortgage Loans Held For Sale IncreaseDecreaseInMortgageLoansHeldForSale	508000	USD
CY2019	us-gaap	Increase Decrease In Mortgage Loans Held For Sale IncreaseDecreaseInMortgageLoansHeldForSale	0	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-6629000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-13768000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	330000	USD
CY2021	us-gaap	Increase Decrease In Interest And Dividends Receivable IncreaseDecreaseInInterestAndDividendsReceivable	-4049000	USD
CY2020	us-gaap	Increase Decrease In Interest And Dividends Receivable IncreaseDecreaseInInterestAndDividendsReceivable	7992000	USD
CY2019	us-gaap	Increase Decrease In Interest And Dividends Receivable IncreaseDecreaseInInterestAndDividendsReceivable	1516000	USD
CY2021	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	62000	USD
CY2020	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-933000	USD
CY2019	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	632000	USD
CY2021	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-6815000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	48539000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	23464000	USD
CY2021	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-30535000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	32791000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	14308000	USD
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	235065000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	192292000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	204747000	USD
CY2021	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-174463000	USD
CY2020	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	619543000	USD
CY2019	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	291857000	USD
CY2021	colb	Investment In Low Income Housing Tax Credit Partnerships InvestmentInLowIncomeHousingTaxCreditPartnerships	1408000	USD
CY2020	colb	Investment In Low Income Housing Tax Credit Partnerships InvestmentInLowIncomeHousingTaxCreditPartnerships	0	USD
CY2019	colb	Investment In Low Income Housing Tax Credit Partnerships InvestmentInLowIncomeHousingTaxCreditPartnerships	0	USD
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	3128233000	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	2118667000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1196895000	USD
CY2021	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	257503000	USD
CY2020	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	USD
CY2019	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	USD
CY2021	us-gaap	Payments To Acquire Loans Receivable PaymentsToAcquireLoansReceivable	279734000	USD
CY2020	us-gaap	Payments To Acquire Loans Receivable PaymentsToAcquireLoansReceivable	50035000	USD
CY2019	us-gaap	Payments To Acquire Loans Receivable PaymentsToAcquireLoansReceivable	57075000	USD
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	6125000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	8720000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	8447000	USD
CY2021	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	1000	USD
CY2020	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	53240000	USD
CY2019	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	273800000	USD
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	89219000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	194697000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	259554000	USD
CY2021	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	0	USD
CY2020	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	3000000	USD
CY2019	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	0	USD
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	764253000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	603129000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	428025000	USD
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	107578000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	0	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	0	USD
CY2021	colb	Proceeds From Sales Of Loans Held For Investment And Other Assets ProceedsFromSalesOfLoansHeldForInvestmentAndOtherAssets	15880000	USD
CY2020	colb	Proceeds From Sales Of Loans Held For Investment And Other Assets ProceedsFromSalesOfLoansHeldForInvestmentAndOtherAssets	2948000	USD
CY2019	colb	Proceeds From Sales Of Loans Held For Investment And Other Assets ProceedsFromSalesOfLoansHeldForInvestmentAndOtherAssets	8634000	USD
CY2021	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	7464000	USD
CY2020	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	91080000	USD
CY2019	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	251640000	USD
CY2021	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	132000	USD
CY2020	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	1074000	USD
CY2019	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	6506000	USD
CY2021	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	671000	USD
CY2020	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	1050000	USD
CY2019	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	8265000	USD
CY2021	colb	Proceeds From Termination Of Cash Flow Hedging Instrument ProceedsFromTerminationOfCashFlowHedgingInstrument	0	USD
CY2020	colb	Proceeds From Termination Of Cash Flow Hedging Instrument ProceedsFromTerminationOfCashFlowHedgingInstrument	34442000	USD
CY2019	colb	Proceeds From Termination Of Cash Flow Hedging Instrument ProceedsFromTerminationOfCashFlowHedgingInstrument	0	USD
CY2021	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	154984000	USD
CY2020	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	0	USD
CY2019	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	0	USD
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-2358360000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1918785000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-865450000	USD
CY2021	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	2402669000	USD
CY2020	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	3185167000	USD
CY2019	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	226958000	USD
CY2021	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	12154000	USD
CY2020	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	9422000	USD
CY2019	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	3343000	USD
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	2350000	USD
CY2020	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	2028000	USD
CY2019	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	2025000	USD
CY2021	us-gaap	Proceeds From Federal Home Loan Bank Advances ProceedsFromFederalHomeLoanBankAdvances	30000	USD
CY2020	us-gaap	Proceeds From Federal Home Loan Bank Advances ProceedsFromFederalHomeLoanBankAdvances	1331000000	USD
CY2019	us-gaap	Proceeds From Federal Home Loan Bank Advances ProceedsFromFederalHomeLoanBankAdvances	6845000000	USD
CY2021	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	40000	USD
CY2020	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	222010000	USD
CY2019	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	36000000	USD
CY2021	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	0	USD
CY2020	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	9222000	USD
CY2019	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	100000	USD
CY2021	us-gaap	Payments For Federal Home Loan Bank Advances PaymentsForFederalHomeLoanBankAdvances	30000	USD
CY2020	us-gaap	Payments For Federal Home Loan Bank Advances PaymentsForFederalHomeLoanBankAdvances	2277000000	USD
CY2019	us-gaap	Payments For Federal Home Loan Bank Advances PaymentsForFederalHomeLoanBankAdvances	6291000000	USD
CY2021	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	40000	USD
CY2020	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	222010000	USD
CY2019	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	36000000	USD
CY2021	us-gaap	Repayments Of Other Debt RepaymentsOfOtherDebt	0	USD
CY2020	us-gaap	Repayments Of Other Debt RepaymentsOfOtherDebt	9222000	USD
CY2019	us-gaap	Repayments Of Other Debt RepaymentsOfOtherDebt	100000	USD
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	83790000	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	95509000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	101911000	USD
CY2021	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	35000000	USD
CY2020	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	USD
CY2019	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	USD
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	20000000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	50834000	USD
CY2021	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	4140000	USD
CY2020	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	2522000	USD
CY2019	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	2792000	USD
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	2294243000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	2132586000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	630789000	USD
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	170948000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	406093000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-29914000	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
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	277587000	USD
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	824714000	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
CY2021	us-gaap	Interest Paid Net InterestPaidNet	8484000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	18631000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	35916000	USD
CY2021	us-gaap	Income Taxes Paid IncomeTaxesPaid	60562000	USD
CY2020	us-gaap	Income Taxes Paid IncomeTaxesPaid	43287000	USD
CY2019	us-gaap	Income Taxes Paid IncomeTaxesPaid	47375000	USD
CY2021	colb	Securities Transfer From Afs To Htm Fair Value SecuritiesTransferFromAFSToHTMFairValue	2012123000	USD
CY2020	colb	Securities Transfer From Afs To Htm Fair Value SecuritiesTransferFromAFSToHTMFairValue	0	USD
CY2019	colb	Securities Transfer From Afs To Htm Fair Value SecuritiesTransferFromAFSToHTMFairValue	0	USD
CY2021	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	0	USD
CY2020	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	1033000	USD
CY2019	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	386000	USD
CY2021	us-gaap	Stock Issued1 StockIssued1	256061000	USD
CY2020	us-gaap	Stock Issued1 StockIssued1	0	USD
CY2019	us-gaap	Stock Issued1 StockIssued1	0	USD
CY2021	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	63000	USD
CY2020	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	302000	USD
CY2019	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	451000	USD
CY2021	colb	Changeindividendspayableonunvestedshares Changeindividendspayableonunvestedshares	51000	USD
CY2020	colb	Changeindividendspayableonunvestedshares Changeindividendspayableonunvestedshares	706000	USD
CY2019	colb	Changeindividendspayableonunvestedshares Changeindividendspayableonunvestedshares	354000	USD
CY2021Q4	colb	Number Of Branch Locations NumberOfBranchLocations	153	location
CY2021	colb	Number Of Days Used To Determine Treatment As Cash Equivalent NumberOfDaysUsedToDetermineTreatmentAsCashEquivalent	P90D
CY2021Q4	colb	Fhl Bmembershipstockpurchaserequirementcap FHLBmembershipstockpurchaserequirementcap	10000000	USD
CY2021Q4	colb	Federal Home Loan Bankstockparvalue FederalHomeLoanBankstockparvalue	100	USD
CY2021	colb	Numberof Daysof Delinquencyat Which Loans Are Categorized As Non Accrual Status NumberofDaysofDelinquencyatWhichLoansAreCategorizedAsNonAccrualStatus	P90D
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Policy For Uncollectible Amounts FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts	<div style="margin-top:9pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%">Allowance for Credit Losses</span></div><div style="margin-top:9pt;text-indent:24.75pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses under ASC 326 is an accounting estimate of expected losses over the contractual life of assets carried at amortized cost within the Company’s loan portfolio at the balance sheet date. Financial assets (or group of financial assets) measured at amortized cost must be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset to present the net carrying value at the amount expected to be collected on the financial asset.</span></div><div style="margin-top:9pt;text-indent:24.75pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The quantitative allowance is calculated using a DCF approach with a probability of default methodology. The probability of default is an assumption derived from regression models which determines the relationship between historical defaults and certain economic variables. The Company determines a reasonable and supportable forecast and applies that forecast to the regression model to determine defaults over the forecast period. The Company leverages economic projections from an independent third-party provider on a quarterly basis that are vetted by the Company through quantifiable analysis and comparisons are evaluated by a committee before a final scenario is determined for the 18 month reasonable and supportable forecast period used by the Company. Following the forecast period, the economic variables used to calculate the probability of default reverts to its historical mean using a straight-line basis constructed on each macroeconomic factor’s absolute historical quarterly change at a constant rate. Other assumptions relevant to the discounted cash flow model to derive the quantitative allowance include the loss given default, which is the estimate of loss for a defaulted loan, and the discount rate applied to future cash flows. The DCF model calculates the net present value of each loan using both the contractual and expected cash flows, respectively.</span></div><div style="margin-top:9pt;text-indent:22.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">In addition to the quantitative portion of the allowance for credit losses, the Company also considers the effects of the following qualitative factors in its calculation of expected losses in the loan portfolio:</span></div><div style="margin-top:9pt;padding-left:49.5pt;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:10pt">Economic and business conditions;</span></div><div style="padding-left:49.5pt;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:10pt">Concentration of credit;</span></div><div style="padding-left:49.5pt;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:10pt">Lending management and staff;</span></div><div style="padding-left:49.5pt;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:10pt">Lending policies and procedures;</span></div><div style="padding-left:49.5pt;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:10pt">Loss and recovery trends;</span></div><div style="padding-left:49.5pt;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:10pt">Nature and volume of the portfolio;</span></div><div style="padding-left:49.5pt;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:10pt">Trends in problem loans, loan delinquencies and nonaccrual loans;</span></div><div style="padding-left:49.5pt;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:10pt">Quality of internal loan review; and</span></div><div style="padding-left:49.5pt;text-indent:-13.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:10pt">Other external factors such as the effect of economic stimulus and loan modification programs.</span></div><div style="margin-top:9pt;text-indent:24.75pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The qualitative factor methodology is based on quantitative metrics, but also includes a high degree of subjectivity and changes in any of the metrics could have a significant impact on our calculation of the allowance. </span></div>Loans for which repayment is expected to be provided substantially through the operation or sale of collateral are considered collateral-dependent. The allowance for credit losses for collateral-dependent loans is measured on the basis of the fair value of the collateral when foreclosure is probable.
CY2021	us-gaap	Business Acquisitions Pro Forma Revenue BusinessAcquisitionsProFormaRevenue	664875000	USD
CY2020	us-gaap	Business Acquisitions Pro Forma Revenue BusinessAcquisitionsProFormaRevenue	660857000	USD
CY2021	us-gaap	Business Acquisitions Pro Forma Net Income Loss BusinessAcquisitionsProFormaNetIncomeLoss	221637000	USD
CY2020	us-gaap	Business Acquisitions Pro Forma Net Income Loss BusinessAcquisitionsProFormaNetIncomeLoss	164087000	USD
CY2021	us-gaap	Business Acquisition Pro Forma Earnings Per Share Basic BusinessAcquisitionProFormaEarningsPerShareBasic	2.85
CY2020	us-gaap	Business Acquisition Pro Forma Earnings Per Share Basic BusinessAcquisitionProFormaEarningsPerShareBasic	2.11
CY2021	us-gaap	Business Acquisition Pro Forma Earnings Per Share Diluted BusinessAcquisitionProFormaEarningsPerShareDiluted	2.84
CY2020	us-gaap	Business Acquisition Pro Forma Earnings Per Share Diluted BusinessAcquisitionProFormaEarningsPerShareDiluted	2.10
CY2021Q4	colb	Number Of Issuances Of Securities Exceeding Shareholders Equity Threshold NumberOfIssuancesOfSecuritiesExceedingShareholdersEquityThreshold	0	issuance
CY2021Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	5898041000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	70839000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	57881000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	5910999000	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost After Allowance For Credit Loss DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss	2148327000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	50000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	25771000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	2122606000	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 Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	89219000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	194697000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	259554000	USD
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	751000	USD
CY2020	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	471000	USD
CY2021	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	0	USD
CY2020	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	16425000	USD
CY2019	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	3357000	USD
CY2021	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	437000	USD
CY2020	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	186000	USD
CY2019	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	1225000	USD
CY2019	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	0	USD
CY2021	us-gaap	Gain Loss On Investments GainLossOnInvestments	314000	USD
CY2020	us-gaap	Gain Loss On Investments GainLossOnInvestments	16710000	USD
CY2019	us-gaap	Gain Loss On Investments GainLossOnInvestments	2132000	USD
CY2021	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	0	USD
CY2020	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	16425000	USD
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CY2019	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	0	USD
CY2021	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	0	USD
CY2020	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	13425000	USD
CY2019	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	0	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	86113000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	86855000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount	0	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	0	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	961029000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	977757000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount	46085000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	45307000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	1522735000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	1538002000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount	1256426000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	1240587000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	3328164000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	3308385000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount	845816000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue	836712000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	5898041000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	5910999000	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost After Allowance For Credit Loss DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss	2148327000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	2122606000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Restricted DebtSecuritiesAvailableForSaleRestricted	962788000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Restricted DebtSecuritiesAvailableForSaleRestricted	861574000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	3195732000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	43236000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	383754000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	14645000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	3579486000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	57881000	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
CY2021	colb	Visa Class Bsharessharessold VisaClassBsharessharessold	17360	shares
CY2021Q4	colb	Visa Class Bsharesremainingshares VisaClassBsharesremainingshares	77683	shares
CY2021Q4	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	13400000	USD
CY2021Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	10641937000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	9427660000	USD
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	155578000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	149140000	USD
CY2021Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	10486359000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	9278520000	USD
CY2021Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	23041000	USD
CY2021Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	10641937000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	34806000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	9427660000	USD
CY2021	colb	Financing Receivable Accrued Interest Reversed Through Interest Income FinancingReceivableAccruedInterestReversedThroughInterestIncome	673000	USD
CY2020	colb	Financing Receivable Accrued Interest Reversed Through Interest Income FinancingReceivableAccruedInterestReversedThroughInterestIncome	2000000	USD
CY2019	colb	Financing Receivable Accrued Interest Reversed Through Interest Income FinancingReceivableAccruedInterestReversedThroughInterestIncome	1671000	USD
CY2021Q4	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	9819000	USD
CY2020Q4	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	20911000	USD
CY2021	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	16	Modifications
CY2021	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	3966000	USD
CY2021	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	3966000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	19	Modifications
CY2020	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	7566000	USD
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	7566000	USD
CY2019	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	24	Modifications
CY2019	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	7348000	USD
CY2019	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	7348000	USD
CY2021Q4	colb	Financing Receivable Modifications Additional Commitment To Lend FinancingReceivableModificationsAdditionalCommitmentToLend	1500000	USD
CY2020Q4	colb	Financing Receivable Modifications Additional Commitment To Lend FinancingReceivableModificationsAdditionalCommitmentToLend	651000	USD
CY2021	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	contract
CY2020	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	contract
CY2019	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	1	contract
CY2019	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	26000	USD
CY2021	colb	Loan Modifications Short Term Deferments Not Classified As Tdr Number Of Contracts LoanModificationsShortTermDefermentsNotClassifiedAsTDRNumberOfContracts	4	contract
CY2021	colb	Loan Modifications Short Term Deferments Not Classified As Tdr Net Of Unearned Income LoanModificationsShortTermDefermentsNotClassifiedAsTDRNetOfUnearnedIncome	14100000	USD
CY2021Q4	colb	Paycheck Protection Program Pp Ploansnetofunearnedincome PaycheckProtectionProgramPPPloansnetofunearnedincome	184100000	USD
CY2021Q4	colb	Minimumloanbalanceofnonaccrualcollateraldependentloansconsideredfor Acl MinimumloanbalanceofnonaccrualcollateraldependentloansconsideredforACL	500000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	149140000	USD
CY2021	us-gaap	Financing Receivable Purchased With Credit Deterioration Allowance For Credit Loss At Acquisition Date FinancingReceivablePurchasedWithCreditDeteriorationAllowanceForCreditLossAtAcquisitionDate	2616000	USD
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	9063000	USD
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	8085000	USD
CY2021	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	4800000	USD
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	155578000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	83968000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	21092000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	6932000	USD
CY2020	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	77700000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	149140000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	83369000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	15215000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	12321000	USD
CY2019	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	3493000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	83968000	USD
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Period Increase Decrease FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease	6400000	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
CY2018Q4	colb	Allowance For Unfunded Loan Commitments And Letters Of Credit AllowanceForUnfundedLoanCommitmentsAndLettersOfCredit	4330000	USD
CY2021	colb	Allowance For Loan And Lease Losses Net Changes In Unfunded Commitments And Letters Of Credit Allowance AllowanceForLoanAndLeaseLossesNetChangesInUnfundedCommitmentsAndLettersOfCreditAllowance	200000	USD
CY2020	colb	Allowance For Loan And Lease Losses Net Changes In Unfunded Commitments And Letters Of Credit Allowance AllowanceForLoanAndLeaseLossesNetChangesInUnfundedCommitmentsAndLettersOfCreditAllowance	3300000	USD
CY2019	colb	Allowance For Loan And Lease Losses Net Changes In Unfunded Commitments And Letters Of Credit Allowance AllowanceForLoanAndLeaseLossesNetChangesInUnfundedCommitmentsAndLettersOfCreditAllowance	-900000	USD
CY2021Q4	colb	Allowance For Unfunded Loan Commitments And Letters Of Credit AllowanceForUnfundedLoanCommitmentsAndLettersOfCredit	8500000	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
CY2021Q4	us-gaap	Financing Receivable Originated In Current Fiscal Year FinancingReceivableOriginatedInCurrentFiscalYear	2745438000	USD
CY2021Q4	us-gaap	Financing Receivable Originated In Fiscal Year Before Latest Fiscal Year FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear	1490732000	USD
CY2021Q4	us-gaap	Financing Receivable Originated Two Years Before Latest Fiscal Year FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear	1201138000	USD
CY2021Q4	us-gaap	Financing Receivable Originated Three Years Before Latest Fiscal Year FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear	854212000	USD
CY2021Q4	us-gaap	Financing Receivable Originated Four Years Before Latest Fiscal Year FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear	798466000	USD
CY2021Q4	us-gaap	Financing Receivable Originated Five Or More Years Before Latest Fiscal Year FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear	1751150000	USD
CY2021Q4	us-gaap	Financing Receivable Revolving FinancingReceivableRevolving	1748587000	USD
CY2021Q4	colb	Financing Receivable Revolving Convertedto Term Loans FinancingReceivableRevolvingConvertedtoTermLoans	52214000	USD
CY2021Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	10641937000	USD
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	155578000	USD
CY2021Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	10486359000	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
CY2020Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	553000	USD
CY2019Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	552000	USD
CY2021	colb	Real Estate Acquired Through Foreclosure Transfers In Net Of Write Downs RealEstateAcquiredThroughForeclosureTransfersInNetOfWriteDowns	0	USD
CY2020	colb	Real Estate Acquired Through Foreclosure Transfers In Net Of Write Downs RealEstateAcquiredThroughForeclosureTransfersInNetOfWriteDowns	1033000	USD
CY2021	colb	Transfer Other Real Estate Write Down TransferOtherRealEstateWriteDown	140000	USD
CY2020	colb	Transfer Other Real Estate Write Down TransferOtherRealEstateWriteDown	70000	USD
CY2021	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	132000	USD
CY2020	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	1066000	USD
CY2021	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	100000	USD
CY2020	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	104000	USD
CY2021Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	381000	USD
CY2020Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	553000	USD
CY2021Q4	us-gaap	Mortgage Loans In Process Of Foreclosure Amount MortgageLoansInProcessOfForeclosureAmount	47000	USD
CY2021Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	255000000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	241153000	USD
CY2021Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	82856000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	79094000	USD
CY2021Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	172144000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	162059000	USD
CY2021	us-gaap	Depreciation And Amortization DepreciationAndAmortization	11000000	USD
CY2020	us-gaap	Depreciation And Amortization DepreciationAndAmortization	10700000	USD
CY2019	us-gaap	Depreciation And Amortization DepreciationAndAmortization	10300000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	765842000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	765842000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	765842000	USD
CY2021	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	57330000	USD
CY2020	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	0	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	0	USD
CY2021Q4	us-gaap	Goodwill Goodwill	823172000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	765842000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	765842000	USD
CY2021Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	919000	USD
CY2020Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	919000	USD
CY2019Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	919000	USD
CY2021Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	34647000	USD
CY2020Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	26734000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	35458000	USD
CY2021Q4	colb	Goodwill And Intangible Assets Total GoodwillAndIntangibleAssetsTotal	857819000	USD
CY2020Q4	colb	Goodwill And Intangible Assets Total GoodwillAndIntangibleAssetsTotal	792576000	USD
CY2019Q4	colb	Goodwill And Intangible Assets Total GoodwillAndIntangibleAssetsTotal	801300000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	8698000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	7082000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	5673000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	4366000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	3225000	USD
CY2021Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P7Y6M
CY2021Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.024
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	12500000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	11200000	USD
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	7200000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	13900000	USD
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	11760000	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	11073000	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	10851000	USD
CY2021	us-gaap	Variable Lease Cost VariableLeaseCost	1800000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	1732000	USD
CY2019	us-gaap	Variable Lease Cost VariableLeaseCost	1805000	USD
CY2021	us-gaap	Sublease Income SubleaseIncome	1562000	USD
CY2020	us-gaap	Sublease Income SubleaseIncome	1454000	USD
CY2019	us-gaap	Sublease Income SubleaseIncome	1182000	USD
CY2021	us-gaap	Lease Cost LeaseCost	11998000	USD
CY2020	us-gaap	Lease Cost LeaseCost	11351000	USD
CY2019	us-gaap	Lease Cost LeaseCost	11474000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	12477000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	10845000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	9926000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	8616000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	7395000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	23753000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	73012000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	6637000	USD
CY2021Q4	us-gaap	Noninterest Bearing Deposit Liabilities Domestic NoninterestBearingDepositLiabilitiesDomestic	8856714000	USD
CY2020Q4	us-gaap	Noninterest Bearing Deposit Liabilities Domestic NoninterestBearingDepositLiabilitiesDomestic	6913214000	USD
CY2021Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	3525299000	USD
CY2020Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	2780922000	USD
CY2021Q4	us-gaap	Interest Bearing Domestic Deposit Demand InterestBearingDomesticDepositDemand	1999407000	USD
CY2020Q4	us-gaap	Interest Bearing Domestic Deposit Demand InterestBearingDomesticDepositDemand	1433083000	USD
CY2021Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	1617546000	USD
CY2020Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	1169721000	USD
CY2021Q4	colb	Interestbearingpublicfundsotherthancertificatesofdeposit Interestbearingpublicfundsotherthancertificatesofdeposit	779146000	USD
CY2020Q4	colb	Interestbearingpublicfundsotherthancertificatesofdeposit Interestbearingpublicfundsotherthancertificatesofdeposit	656273000	USD
CY2021Q4	colb	Certificates Of Deposit Less Than250000 CertificatesOfDepositLessThan250000	249120000	USD
CY2020Q4	colb	Certificates Of Deposit Less Than250000 CertificatesOfDepositLessThan250000	201805000	USD
CY2021Q4	colb	Certificates Of Deposit250000 Or More CertificatesOfDeposit250000OrMore	160490000	USD
CY2020Q4	colb	Certificates Of Deposit250000 Or More CertificatesOfDeposit250000OrMore	108935000	USD
CY2021Q4	colb	Certificates Of Deposit Insured By Cdars CertificatesOfDepositInsuredByCdars	35611000	USD
CY2020Q4	colb	Certificates Of Deposit Insured By Cdars CertificatesOfDepositInsuredByCdars	23105000	USD
CY2021Q4	colb	Otherbrokeredcertificatesofdeposit Otherbrokeredcertificatesofdeposit	0	USD
CY2020Q4	colb	Otherbrokeredcertificatesofdeposit Otherbrokeredcertificatesofdeposit	5000000	USD
CY2021Q4	colb	Brokered Money Market Accounts BrokeredMoneyMarketAccounts	786046000	USD
CY2020Q4	colb	Brokered Money Market Accounts BrokeredMoneyMarketAccounts	577804000	USD
CY2021Q4	colb	Deposits Before Valuation Adjustment DepositsBeforeValuationAdjustment	18009379000	USD
CY2020Q4	colb	Deposits Before Valuation Adjustment DepositsBeforeValuationAdjustment	13869862000	USD
CY2021Q4	colb	Deposits Valuation Adjustment From Acquisition Accounting DepositsValuationAdjustmentFromAcquisitionAccounting	736000	USD
CY2020Q4	colb	Deposits Valuation Adjustment From Acquisition Accounting DepositsValuationAdjustmentFromAcquisitionAccounting	0	USD
CY2021Q4	us-gaap	Deposits Deposits	18010115000	USD
CY2020Q4	us-gaap	Deposits Deposits	13869862000	USD
CY2021Q4	us-gaap	Deposit Liabilities Reclassified As Loans Receivable1 DepositLiabilitiesReclassifiedAsLoansReceivable1	2400000	USD
CY2020Q4	us-gaap	Deposit Liabilities Reclassified As Loans Receivable1 DepositLiabilitiesReclassifiedAsLoansReceivable1	1200000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	346916000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	53080000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	19791000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	12288000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	13879000	USD
CY2021Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	3000	USD
CY2021Q4	us-gaap	Time Deposits TimeDeposits	445957000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances General Debt Obligations Disclosures Maximum Amount Available FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresMaximumAmountAvailable	2180000000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Advances General Debt Obligations Disclosures Maximum Amount Available FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresMaximumAmountAvailable	2090000000.00	USD
CY2020Q4	colb	Federal Home Loan Bank Advances Maturities Summary By Interest Rate Type Fixed Rate Before Valuation Adjustment FederalHomeLoanBankAdvancesMaturitiesSummaryByInterestRateTypeFixedRateBeforeValuationAdjustment	7000000	USD
CY2021Q4	colb	Federal Home Loan Bank Advances Maturities Summary By Interest Rate Type Fixed Rate Before Valuation Adjustment FederalHomeLoanBankAdvancesMaturitiesSummaryByInterestRateTypeFixedRateBeforeValuationAdjustment	7000000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Average Interest Rate Of Amounts Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateOfAmountsDueWithinOneYearOfBalanceSheetDate	0.0385
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary By Interest Rate Type Fixed Rate Under One Year FederalHomeLoanBankAdvancesMaturitiesSummaryByInterestRateTypeFixedRateUnderOneYear	2000000	USD
CY2021Q4	colb	Federal Home Loan Bank Advances Maturities Summary Average Interest Rate After Ten Years From Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateAfterTenYearsFromBalanceSheetDate	0.0537
CY2021Q4	colb	Federal Home Loan Bank Advances Maturities Summary By Interest Rate Type Fixed Rate After Ten Years FederalHomeLoanBankAdvancesMaturitiesSummaryByInterestRateTypeFixedRateAfterTenYears	5000000	USD
CY2021Q4	colb	Federal Home Loan Bank Advances Maturities Summary By Interest Rate Type Fixed Rate Before Valuation Adjustment FederalHomeLoanBankAdvancesMaturitiesSummaryByInterestRateTypeFixedRateBeforeValuationAdjustment	7000000	USD
CY2021Q4	colb	Federal Home Loan Bank Fixed Rate Advances Valuation Adjustment From Acquisition Accounting FederalHomeLoanBankFixedRateAdvancesValuationAdjustmentFromAcquisitionAccounting	359000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary By Interest Rate Type Fixed Rate FederalHomeLoanBankAdvancesMaturitiesSummaryByInterestRateTypeFixedRate	7359000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	7359000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	7414000	USD
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	953469000	USD
CY2021	us-gaap	Federal Home Loan Bank Advances Activity For Year Average Balance Of Agreements Outstanding FederalHomeLoanBankAdvancesActivityForYearAverageBalanceOfAgreementsOutstanding	7388000	USD
CY2020	us-gaap	Federal Home Loan Bank Advances Activity For Year Average Balance Of Agreements Outstanding FederalHomeLoanBankAdvancesActivityForYearAverageBalanceOfAgreementsOutstanding	341643000	USD
CY2019	us-gaap	Federal Home Loan Bank Advances Activity For Year Average Balance Of Agreements Outstanding FederalHomeLoanBankAdvancesActivityForYearAverageBalanceOfAgreementsOutstanding	469983000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Activity For Year Maximum Outstanding At Any Month End FederalHomeLoanBankAdvancesActivityForYearMaximumOutstandingAtAnyMonthEnd	7409000	USD
CY2021	colb	Look Back Period Under Employee Stock Purchase Plan LookBackPeriodUnderEmployeeStockPurchasePlan	P6M
CY2020Q4	us-gaap	Federal Home Loan Bank Advances Activity For Year Maximum Outstanding At Any Month End FederalHomeLoanBankAdvancesActivityForYearMaximumOutstandingAtAnyMonthEnd	1005464000	USD
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Activity For Year Maximum Outstanding At Any Month End FederalHomeLoanBankAdvancesActivityForYearMaximumOutstandingAtAnyMonthEnd	953469000	USD
CY2021	us-gaap	Federal Home Loan Bank Advances Activity For Year Average Interest Rate For Year FederalHomeLoanBankAdvancesActivityForYearAverageInterestRateForYear	0.0494
CY2020	us-gaap	Federal Home Loan Bank Advances Activity For Year Average Interest Rate For Year FederalHomeLoanBankAdvancesActivityForYearAverageInterestRateForYear	0.0182
CY2019	us-gaap	Federal Home Loan Bank Advances Activity For Year Average Interest Rate For Year FederalHomeLoanBankAdvancesActivityForYearAverageInterestRateForYear	0.0242
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Activity For Year Average Interest Rate At Period End FederalHomeLoanBankAdvancesActivityForYearAverageInterestRateAtPeriodEnd	0.0494
CY2020Q4	us-gaap	Federal Home Loan Bank Advances Activity For Year Average Interest Rate At Period End FederalHomeLoanBankAdvancesActivityForYearAverageInterestRateAtPeriodEnd	0.0494
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Activity For Year Average Interest Rate At Period End FederalHomeLoanBankAdvancesActivityForYearAverageInterestRateAtPeriodEnd	0.0184
CY2021Q4	colb	Federal Reserve Bank Advances Maximum Amount Available FederalReserveBankAdvancesMaximumAmountAvailable	226000000	USD
CY2020Q4	colb	Federal Reserve Bank Advances Maximum Amount Available FederalReserveBankAdvancesMaximumAmountAvailable	234400000	USD
CY2021	colb	Federal Reserve Bank Advances Activityfortheyearaveragebalanceofagreementsoutstanding FederalReserveBankAdvancesActivityfortheyearaveragebalanceofagreementsoutstanding	0	USD
CY2021	colb	Paycheck Protection Program Liquidity Facility Ppplf Borrowing Rate PaycheckProtectionProgramLiquidityFacilityPPPLFBorrowingRate	0.0035
CY2020	colb	Federal Reserve Bank Advances Activityfortheyearaveragebalanceofagreementsoutstanding FederalReserveBankAdvancesActivityfortheyearaveragebalanceofagreementsoutstanding	1100000	USD
CY2019	colb	Federal Reserve Bank Advances Activityfortheyearaveragebalanceofagreementsoutstanding FederalReserveBankAdvancesActivityfortheyearaveragebalanceofagreementsoutstanding	99000	USD
CY2021Q4	us-gaap	Line Of Credit Facility Maximum Borrowing Capacity LineOfCreditFacilityMaximumBorrowingCapacity	15000000	USD
CY2021Q4	us-gaap	Interest Rate Cash Flow Hedge Gain Loss To Be Reclassified During Next12 Months Net InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet	10400000	USD
CY2021	us-gaap	Unrealized Gain Loss On Interest Rate Cash Flow Hedges Pretax Accumulated Other Comprehensive Income Loss UnrealizedGainLossOnInterestRateCashFlowHedgesPretaxAccumulatedOtherComprehensiveIncomeLoss	0	USD
CY2020	us-gaap	Unrealized Gain Loss On Interest Rate Cash Flow Hedges Pretax Accumulated Other Comprehensive Income Loss UnrealizedGainLossOnInterestRateCashFlowHedgesPretaxAccumulatedOtherComprehensiveIncomeLoss	26074000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	10441000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	8418000	USD
CY2021	colb	Gain On Termination Of Interest Rate Collar GainOnTerminationOfInterestRateCollar	34400000	USD
CY2021	colb	Discount On Common Stock Under Employee Stock Purchase Plan Percent DiscountOnCommonStockUnderEmployeeStockPurchasePlanPercent	0.10
CY2021Q4	colb	Repurchaseagreementsamountsoffsetinbalancesheet Repurchaseagreementsamountsoffsetinbalancesheet	0	USD
CY2021Q4	colb	Repurchaseagreementsnetamountpresentedinstatementoffinancialposition Repurchaseagreementsnetamountpresentedinstatementoffinancialposition	86013000	USD
CY2021Q4	us-gaap	Securities Sold Under Agreements To Repurchase Collateral Right To Reclaim Securities SecuritiesSoldUnderAgreementsToRepurchaseCollateralRightToReclaimSecurities	86013000	USD
CY2021Q4	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
CY2021Q4	us-gaap	Secured Borrowings Gross Including Not Subject To Master Netting Arrangement SecuredBorrowingsGrossIncludingNotSubjectToMasterNettingArrangement	86013000	USD
CY2021Q4	us-gaap	Secured Borrowings Gross Difference Amount SecuredBorrowingsGrossDifferenceAmount	0	USD
CY2021	colb	Number Of Look Back Period Under Employee Stock Purchase Plan NumberOfLookBackPeriodUnderEmployeeStockPurchasePlan	2	period
CY2021	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	63586	shares
CY2021	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	2300000	USD
CY2020	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	79297	shares
CY2020	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	2200000	USD
CY2019	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	57201	shares
CY2019	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	2100000	USD
CY2021Q4	colb	Shares Available For Purchase Under Employee Stock Purchase Plan SharesAvailableForPurchaseUnderEmployeeStockPurchasePlan	160273	shares
CY2020Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	27402000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	24914000	USD
CY2021	us-gaap	Defined Benefit Plan Business Combinations And Acquisitions Benefit Obligation DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation	4889000	USD
CY2020	us-gaap	Defined Benefit Plan Business Combinations And Acquisitions Benefit Obligation DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation	0	USD
CY2021	us-gaap	Defined Benefit Plan Actuarial Gain Loss DefinedBenefitPlanActuarialGainLoss	-732000	USD
CY2020	us-gaap	Defined Benefit Plan Actuarial Gain Loss DefinedBenefitPlanActuarialGainLoss	2836000	USD
CY2021	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	1735000	USD
CY2020	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	1887000	USD
CY2021	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	1200000	USD
CY2020	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	2235000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	32094000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	27402000	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
CY2021Q4	us-gaap	Stock Repurchase Program Number Of Shares Authorized To Be Repurchased StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased	3500000	shares
CY2021Q4	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	100000000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	182195000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-136920000	USD
CY2021	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	10113000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-147033000	USD
CY2021Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	35162000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	40367000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	148190000	USD
CY2020	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	6362000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	141828000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	182195000	USD
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-35305000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	77520000	USD
CY2019	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	1848000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	75672000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	40367000	USD
CY2021Q4	colb	Visa Class Bsharesremainingshares VisaClassBsharesremainingshares	77683	shares
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
CY2021	us-gaap	Equity Securities Without Readily Determinable Fair Value Upward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount	0	USD
CY2020	us-gaap	Equity Securities Without Readily Determinable Fair Value Upward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount	13425000	USD
CY2021Q4	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
CY2021Q4	colb	Fair Value Loans Held For Sale Mandatory Delivery Method Fv Option FairValueLoansHeldForSaleMandatoryDeliveryMethodFVOption	9570000	USD
CY2021Q4	colb	Fair Value Fv Option Aggregate Unpaid Balance Loans And Long Term Receivables FairValueFVOptionAggregateUnpaidBalanceLoansAndLongTermReceivables	9401000	USD
CY2021Q4	us-gaap	Fair Value Option Aggregate Differences Loans And Long Term Receivables FairValueOptionAggregateDifferencesLoansAndLongTermReceivables	169000	USD
CY2020	us-gaap	Fair Value Option Changes In Fair Value Gain Loss1 FairValueOptionChangesInFairValueGainLoss1	508000	USD
CY2020Q4	colb	Fair Value Loans Held For Sale Mandatory Delivery Method Fv Option FairValueLoansHeldForSaleMandatoryDeliveryMethodFVOption	14760000	USD
CY2020Q4	colb	Fair Value Fv Option Aggregate Unpaid Balance Loans And Long Term Receivables FairValueFVOptionAggregateUnpaidBalanceLoansAndLongTermReceivables	14252000	USD
CY2020Q4	us-gaap	Fair Value Option Aggregate Differences Loans And Long Term Receivables FairValueOptionAggregateDifferencesLoansAndLongTermReceivables	508000	USD
CY2021	us-gaap	Fair Value Option Changes In Fair Value Gain Loss1 FairValueOptionChangesInFairValueGainLoss1	-339000	USD
CY2019	us-gaap	Fair Value Option Changes In Fair Value Gain Loss1 FairValueOptionChangesInFairValueGainLoss1	0	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	202820000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	154244000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	194451000	USD
CY2021	colb	Earningsallocatedtoparticipatingsecuritiesnonvestedrestrictedshares Earningsallocatedtoparticipatingsecuritiesnonvestedrestrictedshares	330000	USD
CY2020	colb	Earningsallocatedtoparticipatingsecuritiesnonvestedrestrictedshares Earningsallocatedtoparticipatingsecuritiesnonvestedrestrictedshares	712000	USD
CY2019	colb	Earningsallocatedtoparticipatingsecuritiesnonvestedrestrictedshares Earningsallocatedtoparticipatingsecuritiesnonvestedrestrictedshares	1530000	USD
CY2021	colb	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	202490000	USD
CY2020	colb	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	153532000	USD
CY2019	colb	Basic Earnings Allocated To Common Shareholders BasicEarningsAllocatedToCommonShareholders	192921000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	72683000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70835000	shares
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CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.17
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.68
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	202490000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	153532000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	192921000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	72683000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70835000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	71999000	shares
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	190000	shares
CY2020	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	45000	shares
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	33000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	72873000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	70880000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	72032000	shares
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.78
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.17
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.68
CY2021	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	212000	shares
CY2020	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	289000	shares
CY2019	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	8000	shares
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	3050000	shares
CY2021Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	19600000	USD
CY2021	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P1Y7M6D
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue	12600000	USD
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue	8100000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue	8700000	USD
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	0	shares
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	108000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0	shares
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CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0	shares
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CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	14900000	USD
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	10700000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	9300000	USD
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CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	60318000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	51916000	USD
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CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-12078000	USD
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CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	270000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-6629000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-13768000	USD
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CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	14887000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	11658000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	3186000	USD
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CY2021Q4	colb	Deferred Tax Asset Other Real Estate Owned Costs DeferredTaxAssetOtherRealEstateOwnedCosts	50000	USD
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CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	118000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	102000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	2898000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	3304000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	1824000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	278000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	78314000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	70686000	USD
CY2021Q4	colb	Deferred Tax Liabilities Asset Purchase Tax Basis Difference DeferredTaxLiabilitiesAssetPurchaseTaxBasisDifference	5052000	USD
CY2020Q4	colb	Deferred Tax Liabilities Asset Purchase Tax Basis Difference DeferredTaxLiabilitiesAssetPurchaseTaxBasisDifference	6590000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	14510000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	14501000	USD
CY2021Q4	colb	Deferred Tax Liabilities Stock Dividends DeferredTaxLiabilitiesStockDividends	810000	USD
CY2020Q4	colb	Deferred Tax Liabilities Stock Dividends DeferredTaxLiabilitiesStockDividends	789000	USD
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CY2020Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Deferred Financing Costs DeferredTaxLiabilitiesDeferredExpenseDeferredFinancingCosts	5695000	USD
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CY2021Q4	colb	Deferred Tax Liabilites Unrealized Gains On Equity Securities DeferredTaxLiabilitesUnrealizedGainsOnEquitySecurities	3231000	USD
CY2020Q4	colb	Deferred Tax Liabilites Unrealized Gains On Equity Securities DeferredTaxLiabilitesUnrealizedGainsOnEquitySecurities	3147000	USD
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CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	2427000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Derivatives DeferredTaxLiabilitiesDerivatives	5280000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Derivatives DeferredTaxLiabilitiesDerivatives	7591000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	130000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	112000	USD
CY2021Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	59739000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	98215000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	18575000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	27529000	USD
CY2021	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	53867000	USD
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	40402000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
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CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2021	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	6306000	USD
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	-0.02
CY2020	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	5987000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	-0.03
CY2019	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	6771000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	-0.03
CY2021	colb	Income Tax Reconciliation Life Insurance Proceeds IncomeTaxReconciliationLifeInsuranceProceeds	1444000	USD
CY2021	colb	Effective Income Tax Rate Reconciliation Life Insurance Proceeds EffectiveIncomeTaxRateReconciliationLifeInsuranceProceeds	-0.01
CY2020	colb	Income Tax Reconciliation Life Insurance Proceeds IncomeTaxReconciliationLifeInsuranceProceeds	1348000	USD
CY2020	colb	Effective Income Tax Rate Reconciliation Life Insurance Proceeds EffectiveIncomeTaxRateReconciliationLifeInsuranceProceeds	-0.01
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CY2019	colb	Effective Income Tax Rate Reconciliation Life Insurance Proceeds EffectiveIncomeTaxRateReconciliationLifeInsuranceProceeds	-0.01
CY2021	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	7892000	USD
CY2021	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.03
CY2020	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	4844000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.03
CY2019	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	5134000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.02
CY2021	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-320000	USD
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0
CY2020	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	237000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0
CY2019	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	22000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.01
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	53689000	USD
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.21
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	38148000	USD
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.20
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	47160000	USD
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.20
CY2021Q4	us-gaap	Deferred Tax Liability Not Recognized Amount Of Unrecognized Deferred Tax Liability Undistributed Earnings Of Domestic Subsidiaries DeferredTaxLiabilityNotRecognizedAmountOfUnrecognizedDeferredTaxLiabilityUndistributedEarningsOfDomesticSubsidiaries	0	USD
CY2020Q4	us-gaap	Deferred Tax Liability Not Recognized Amount Of Unrecognized Deferred Tax Liability Undistributed Earnings Of Domestic Subsidiaries DeferredTaxLiabilityNotRecognizedAmountOfUnrecognizedDeferredTaxLiabilityUndistributedEarningsOfDomesticSubsidiaries	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	0	USD
CY2021	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	0	USD
CY2021Q4	colb	Federaloperatinglosscarryforwardssettobegintoexpirein2024 Federaloperatinglosscarryforwardssettobegintoexpirein2024	11300000	USD
CY2021Q4	colb	Idahostateoperatinglosscarryforwardssettobegintoexpirein2024 Idahostateoperatinglosscarryforwardssettobegintoexpirein2024	8400000	USD
CY2021Q4	colb	Oregonstateoperatinglosscarryforwardssettobegintoexpirein2024 Oregonstateoperatinglosscarryforwardssettobegintoexpirein2024	61000	USD
CY2021Q4	colb	Capital Conservation Buffer CapitalConservationBuffer	0.0621
CY2021Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	1710981000	USD
CY2021Q4	colb	Common Equity Tier1 Capitalto Risk Weighted Assets CommonEquityTier1CapitaltoRiskWeightedAssets	0.1301
CY2021Q4	us-gaap	Common Equity Tier One Capital Required For Capital Adequacy CommonEquityTierOneCapitalRequiredForCapitalAdequacy	591585000	USD
CY2021Q4	colb	Common Equity Tier1 Risk Based Capital Requiredfor Capital Adequacyto Risk Weighted Assets CommonEquityTier1RiskBasedCapitalRequiredforCapitalAdequacytoRiskWeightedAssets	0.0450
CY2021Q4	colb	Common Equity Tier One Capital Requiredfor Capital Adequacyminimumrequiredplusfullyphasedincapitalconservationbuffer CommonEquityTierOneCapitalRequiredforCapitalAdequacyminimumrequiredplusfullyphasedincapitalconservationbuffer	920244000	USD
CY2021Q4	colb	Common Equity Tier1 Risk Based Capital Requiredfor Capital Adequacyto Risk Weighted Assetspluscapitalconservationbufferfullyphasedin CommonEquityTier1RiskBasedCapitalRequiredforCapitalAdequacytoRiskWeightedAssetspluscapitalconservationbufferfullyphasedin	0.0700
CY2021Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	1710981000	USD
CY2021Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.1301
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CY2021Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0600
CY2021Q4	colb	Tier One Risk Based Capital Requiredfor Capital Adequacypluscapitalconservationbufferfullyphasedin TierOneRiskBasedCapitalRequiredforCapitalAdequacypluscapitalconservationbufferfullyphasedin	1117439000	USD
CY2021Q4	colb	Tier One Based Capital Requiredfor Capital Adequacyto Risk Weighted Assetspluscapitalconservationbufferfullyphasedin TierOneBasedCapitalRequiredforCapitalAdequacytoRiskWeightedAssetspluscapitalconservationbufferfullyphasedin	0.0850
CY2021Q4	us-gaap	Capital Capital	1868192000	USD
CY2021Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1421
CY2021Q4	us-gaap	Capital Required For Capital Adequacy CapitalRequiredForCapitalAdequacy	1051707000	USD
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CY2021Q4	colb	Capital Requiredfor Capital Adequacypluscapitalconservationbufferfullyphasedin CapitalRequiredforCapitalAdequacypluscapitalconservationbufferfullyphasedin	1380366000	USD
CY2021Q4	colb	Capital Requiredfor Capital Adequacyto Risk Weighted Assetspluscapitalconservationbufferfullyphasedin CapitalRequiredforCapitalAdequacytoRiskWeightedAssetspluscapitalconservationbufferfullyphasedin	0.1050
CY2021Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	1710981000	USD
CY2021Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.0855
CY2021Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	800615000	USD
CY2021Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2021Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	800615000	USD
CY2021Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2020Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	1390958000	USD
CY2020Q4	colb	Common Equity Tier1 Capitalto Risk Weighted Assets CommonEquityTier1CapitaltoRiskWeightedAssets	0.1288
CY2020Q4	us-gaap	Common Equity Tier One Capital Required For Capital Adequacy CommonEquityTierOneCapitalRequiredForCapitalAdequacy	486080000	USD
CY2020Q4	colb	Common Equity Tier1 Risk Based Capital Requiredfor Capital Adequacyto Risk Weighted Assets CommonEquityTier1RiskBasedCapitalRequiredforCapitalAdequacytoRiskWeightedAssets	0.0450
CY2020Q4	colb	Common Equity Tier One Capital Requiredfor Capital Adequacyminimumrequiredplusfullyphasedincapitalconservationbuffer CommonEquityTierOneCapitalRequiredforCapitalAdequacyminimumrequiredplusfullyphasedincapitalconservationbuffer	756125000	USD
CY2020Q4	colb	Common Equity Tier1 Risk Based Capital Requiredfor Capital Adequacyto Risk Weighted Assetspluscapitalconservationbufferfullyphasedin CommonEquityTier1RiskBasedCapitalRequiredforCapitalAdequacytoRiskWeightedAssetspluscapitalconservationbufferfullyphasedin	0.0700
CY2020Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	1390958000	USD
CY2020Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.1288
CY2020Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy TierOneRiskBasedCapitalRequiredForCapitalAdequacy	648107000	USD
CY2020Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0600
CY2020Q4	colb	Tier One Risk Based Capital Requiredfor Capital Adequacypluscapitalconservationbufferfullyphasedin TierOneRiskBasedCapitalRequiredforCapitalAdequacypluscapitalconservationbufferfullyphasedin	918152000	USD
CY2020Q4	colb	Tier One Based Capital Requiredfor Capital Adequacyto Risk Weighted Assetspluscapitalconservationbufferfullyphasedin TierOneBasedCapitalRequiredforCapitalAdequacytoRiskWeightedAssetspluscapitalconservationbufferfullyphasedin	0.0850
CY2020Q4	us-gaap	Capital Capital	1561020000	USD
CY2020Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1445
CY2020Q4	us-gaap	Capital Required For Capital Adequacy CapitalRequiredForCapitalAdequacy	864143000	USD
CY2020Q4	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0800
CY2020Q4	colb	Capital Requiredfor Capital Adequacypluscapitalconservationbufferfullyphasedin CapitalRequiredforCapitalAdequacypluscapitalconservationbufferfullyphasedin	1134187000	USD
CY2020Q4	colb	Capital Requiredfor Capital Adequacyto Risk Weighted Assetspluscapitalconservationbufferfullyphasedin CapitalRequiredforCapitalAdequacytoRiskWeightedAssetspluscapitalconservationbufferfullyphasedin	0.1050
CY2020Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	1390958000	USD
CY2020Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.0886
CY2020Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	628112000	USD
CY2020Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2020Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	628112000	USD
CY2020Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2021	colb	Depositaccountandtreasurymanagementfees Depositaccountandtreasurymanagementfees	27107000	USD
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CY2021	colb	Cardrevenue Cardrevenue	18503000	USD
CY2019	colb	Cardrevenue Cardrevenue	15198000	USD
CY2020	colb	Cardrevenue Cardrevenue	13928000	USD
CY2021	colb	Financialservicesandtrustrevenue Financialservicesandtrustrevenue	15753000	USD
CY2020	colb	Financialservicesandtrustrevenue Financialservicesandtrustrevenue	12830000	USD
CY2019	colb	Financialservicesandtrustrevenue Financialservicesandtrustrevenue	12799000	USD
CY2021	colb	Revenuefromcontractswithcustomers Revenuefromcontractswithcustomers	61363000	USD
CY2020	colb	Revenuefromcontractswithcustomers Revenuefromcontractswithcustomers	53777000	USD
CY2019	colb	Revenuefromcontractswithcustomers Revenuefromcontractswithcustomers	63692000	USD
CY2021	colb	Noninterestincomeexcludingrevenuefromcontractswithcustomers Noninterestincomeexcludingrevenuefromcontractswithcustomers	32731000	USD
CY2020	colb	Noninterestincomeexcludingrevenuefromcontractswithcustomers Noninterestincomeexcludingrevenuefromcontractswithcustomers	50723000	USD
CY2019	colb	Noninterestincomeexcludingrevenuefromcontractswithcustomers Noninterestincomeexcludingrevenuefromcontractswithcustomers	33489000	USD
CY2021	us-gaap	Noninterest Income NoninterestIncome	94094000	USD
CY2020	us-gaap	Noninterest Income NoninterestIncome	104500000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	97181000	USD
CY2021	dei	Auditor Name AuditorName	Deloitte & Touche LLP
CY2021	dei	Auditor Location AuditorLocation	Seattle, Washington
CY2021	dei	Auditor Firm AuditorFirmId	34

Files In Submission

Name	View Source	Status
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$COLB
COLUMBIA BANKING SYSTEM, INC. Stock $colb

2021 Q3 Form 10-K Financial Statement

#000088734322000038 Filed on February 25, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$COLB COLUMBIA BANKING SYSTEM, INC. Stock $colb

2021 Q3 Form 10-K Financial Statement

#000088734322000038 Filed on February 25, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$COLB
COLUMBIA BANKING SYSTEM, INC. Stock $colb