$BHLB
BERKSHIRE HILLS BANCORP INC Stock $bhlb

$bhlb Overview Financials Valuation SEC Filings Company Website

2023 Q1 Form 10-K Financial Statement

#000110813423000006 Filed on March 01, 2023

Income Statement

Concept	2023 Q1	2022 Q4	2022 Q2
Revenue	$114.1M	$117.7M	$97.71M
YoY Change	27.18%	29.79%	0.31%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development	$9.471M		$8.611M
YoY Change	11.07%		4.83%
% of Gross Profit
Depreciation & Amortization	$3.428M	$3.596M	$3.714M
YoY Change	-8.95%	-7.79%	-9.41%
% of Gross Profit
Operating Expenses	$9.471M		$8.611M
YoY Change	11.07%		4.83%
Operating Profit
YoY Change
Interest Expense	$34.78M	$19.29M	$6.021M
YoY Change	503.87%	194.62%	-39.61%
% of Operating Profit
Other Income/Expense, Net	$359.0K		$1.812M
YoY Change	-88.66%		-18.05%
Pretax Income	$33.19M	$35.73M	$29.23M
YoY Change	31.72%	46.96%	2.46%
Income Tax	$5.548M	$5.227M	$6.119M
% Of Pretax Income	16.72%	14.63%	20.93%
Net Earnings	$27.64M	$30.51M	$23.12M
YoY Change	36.84%	50.66%	6.84%
Net Earnings / Revenue	24.21%	25.91%	23.66%
Basic Earnings Per Share	$0.63	$0.69	$0.50
Diluted Earnings Per Share	$0.63	$685.8K	$501.4K
COMMON SHARES
Basic Shares Outstanding	44.47M shares	45.03M shares	47.32M shares
Diluted Shares Outstanding	44.04M shares	44.48M shares	46.10M shares

Balance Sheet

Concept	2023 Q1	2022 Q4	2022 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments		$698.2M
YoY Change		-57.51%
Cash & Equivalents	$1.007B	$685.4M	$871.0M
Short-Term Investments		$12.86M
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$78.71M	$85.22M	$142.3M
YoY Change	-15.34%	-9.71%	35.89%
Goodwill
YoY Change
Intangibles	$23.28M	$24.48M
YoY Change	-17.83%	-17.34%
Long-Term Investments
YoY Change
Other Assets	$8.220M	$3.260M	$5.386M
YoY Change	106.12%	-94.28%	-98.06%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$12.32B	$11.66B	$11.58B
YoY Change	1.84%	0.93%	-5.66%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$55.26M	$53.74M	$55.99M
YoY Change	-3.2%	-4.04%	-8.22%
Deferred Revenue
YoY Change
Short-Term Debt	$900.0M	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$55.26M	$53.74M	$55.99M
YoY Change	-3.2%	-4.04%	-8.22%
LONG-TERM LIABILITIES
Long-Term Debt	$130.3M	$125.5M	$205.2M
YoY Change	21.44%	17.3%	90.04%
Other Long-Term Liabilities	$167.0M	$256.0M	$130.5M
YoY Change	33.6%	101.59%	-83.63%
Total Long-Term Liabilities	$297.3M	$381.5M	$335.7M
YoY Change	27.98%	63.05%	-62.9%
TOTAL LIABILITIES
Total Short-Term Liabilities	$55.26M	$53.74M	$55.99M
Total Long-Term Liabilities	$297.3M	$381.5M	$335.7M
Total Liabilities	$11.32B	$10.71B	$10.56B
YoY Change	2.92%	3.24%	-4.8%
SHAREHOLDERS EQUITY
Retained Earnings	-$51.40M	-$71.43M
YoY Change	-58.99%	-48.75%
Common Stock	$1.425B	$1.425B
YoY Change	0.06%	0.05%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$995.5M	$954.1M	$1.014B
YoY Change
Total Liabilities & Shareholders Equity	$12.32B	$11.66B	$11.58B
YoY Change	1.84%	0.93%	-5.66%

Cashflow Statement

Concept	2023 Q1	2022 Q4	2022 Q2
OPERATING ACTIVITIES
Net Income	$27.64M	$30.51M	$23.12M
YoY Change	36.84%	50.66%	6.84%
Depreciation, Depletion And Amortization	$3.428M	$3.596M	$3.714M
YoY Change	-8.95%	-7.79%	-9.41%
Cash From Operating Activities	$37.31M	$35.01M	-$2.409M
YoY Change	123.49%	52.2%	-106.01%
INVESTING ACTIVITIES
Capital Expenditures	$753.0K	$765.0K	-$730.0K
YoY Change			-204.29%
Acquisitions
YoY Change
Other Investing Activities	-$339.2M	-$350.1M	-$252.3M
YoY Change	-49.77%	53.91%	-164.49%
Cash From Investing Activities	-$340.0M	-$350.9M	-$253.1M
YoY Change	-49.66%	54.25%	-164.56%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	$623.9M	306.3M	-480.8M
YoY Change	-2.24%	-204.88%	-4.84%
NET CHANGE
Cash From Operating Activities	$37.31M	35.01M	-2.409M
Cash From Investing Activities	-$340.0M	-350.9M	-253.1M
Cash From Financing Activities	$623.9M	306.3M	-480.8M
Net Change In Cash	$321.2M	-9.558M	-736.2M
YoY Change	-1662.59%	-98.08%	907.16%
FREE CASH FLOW
Cash From Operating Activities	$37.31M	$35.01M	-$2.409M
Capital Expenditures	$753.0K	$765.0K	-$730.0K
Free Cash Flow	$36.56M	$34.24M	-$1.679M
YoY Change	118.98%	48.87%	-104.26%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2022	dei	Entity File Number EntityFileNumber	001-15781
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CY2022	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
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CY2020	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	316782000	usd
CY2022	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	6973000	usd
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	6631000	usd
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	2597000	usd
CY2022	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	-2031000	usd
CY2021	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	-787000	usd
CY2020	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	-7520000	usd
CY2022	bhlb	Gain Loss On Disposition Of Business And Assets GainLossOnDispositionOfBusinessAndAssets	0	usd
CY2021	bhlb	Gain Loss On Disposition Of Business And Assets GainLossOnDispositionOfBusinessAndAssets	52942000	usd
CY2020	bhlb	Gain Loss On Disposition Of Business And Assets GainLossOnDispositionOfBusinessAndAssets	1240000	usd
CY2022	us-gaap	Noninterest Income NoninterestIncome	68937000	usd
CY2021	us-gaap	Noninterest Income NoninterestIncome	143248000	usd
CY2020	us-gaap	Noninterest Income NoninterestIncome	66307000	usd
CY2022	us-gaap	Revenues Revenues	413534000	usd
CY2021	us-gaap	Revenues Revenues	434414000	usd
CY2020	us-gaap	Revenues Revenues	383089000	usd
CY2022	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	11000000	usd
CY2021	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-500000	usd
CY2020	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	75878000	usd
CY2022	us-gaap	Labor And Related Expense LaborAndRelatedExpense	152741000	usd
CY2021	us-gaap	Labor And Related Expense LaborAndRelatedExpense	150589000	usd
CY2020	us-gaap	Labor And Related Expense LaborAndRelatedExpense	147840000	usd
CY2022	bhlb	Occupancy And Equipment OccupancyAndEquipment	37638000	usd
CY2021	bhlb	Occupancy And Equipment OccupancyAndEquipment	41782000	usd
CY2020	bhlb	Occupancy And Equipment OccupancyAndEquipment	43359000	usd
CY2022	us-gaap	Communications And Information Technology CommunicationsAndInformationTechnology	35586000	usd
CY2021	us-gaap	Communications And Information Technology CommunicationsAndInformationTechnology	33803000	usd
CY2020	us-gaap	Communications And Information Technology CommunicationsAndInformationTechnology	32364000	usd
CY2022	us-gaap	Marketing Expense MarketingExpense	5103000	usd
CY2021	us-gaap	Marketing Expense MarketingExpense	2749000	usd
CY2020	us-gaap	Marketing Expense MarketingExpense	3703000	usd
CY2022	us-gaap	Professional Fees ProfessionalFees	12043000	usd
CY2021	us-gaap	Professional Fees ProfessionalFees	15860000	usd
CY2020	us-gaap	Professional Fees ProfessionalFees	11907000	usd
CY2022	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	3105000	usd
CY2021	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	3759000	usd
CY2020	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	5876000	usd
CY2022	bhlb	Other Real Estate Owned OtherRealEstateOwned	36000	usd
CY2021	bhlb	Other Real Estate Owned OtherRealEstateOwned	17000	usd
CY2020	bhlb	Other Real Estate Owned OtherRealEstateOwned	125000	usd
CY2022	us-gaap	Adjustment For Amortization AdjustmentForAmortization	5134000	usd
CY2021	us-gaap	Adjustment For Amortization AdjustmentForAmortization	5200000	usd
CY2020	us-gaap	Adjustment For Amortization AdjustmentForAmortization	6181000	usd
CY2022	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2021	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2020	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	553762000	usd
CY2022	us-gaap	Other Nonrecurring Expense OtherNonrecurringExpense	8909000	usd
CY2021	us-gaap	Other Nonrecurring Expense OtherNonrecurringExpense	5781000	usd
CY2020	us-gaap	Other Nonrecurring Expense OtherNonrecurringExpense	5839000	usd
CY2022	us-gaap	Other Noninterest Expense OtherNoninterestExpense	28421000	usd
CY2021	us-gaap	Other Noninterest Expense OtherNoninterestExpense	26353000	usd
CY2020	us-gaap	Other Noninterest Expense OtherNoninterestExpense	29283000	usd
CY2022	us-gaap	Noninterest Expense NoninterestExpense	288716000	usd
CY2021	us-gaap	Noninterest Expense NoninterestExpense	285893000	usd
CY2020	us-gaap	Noninterest Expense NoninterestExpense	840239000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	113818000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	149021000	usd
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	-533028000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21285000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30357000	usd
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-19853000	usd
CY2022	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	92533000	usd
CY2021	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	118664000	usd
CY2020	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-513175000	usd
CY2022	us-gaap	Discontinued Operation Income Loss From Discontinued Operation During Phase Out Period Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodBeforeIncomeTax	0	usd
CY2021	us-gaap	Discontinued Operation Income Loss From Discontinued Operation During Phase Out Period Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodBeforeIncomeTax	0	usd
CY2020	us-gaap	Discontinued Operation Income Loss From Discontinued Operation During Phase Out Period Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodBeforeIncomeTax	-26855000	usd
CY2022	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	0	usd
CY2021	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	0	usd
CY2020	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	-7013000	usd
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	0	usd
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	0	usd
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-19842000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	92533000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	118664000	usd
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-533017000	usd
CY2022	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	0	usd
CY2021	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	0	usd
CY2020	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	313000	usd
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	92533000	usd
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	118664000	usd
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-533330000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	2.03
CY2021	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	2.41
CY2020	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-10.21
CY2022	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	0
CY2021	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	0
CY2020	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	-0.39
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.03
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.41
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-10.60
CY2022	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	2.02
CY2021	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	2.39
CY2020	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-10.21
CY2022	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare	0
CY2021	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare	0
CY2020	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare	-0.39
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.02
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.39
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-10.60
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	45564000	shares
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	49240000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	50270000	shares
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	45914000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	49554000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	50270000	shares
CY2022	us-gaap	Net Income Loss NetIncomeLoss	92533000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	118664000	usd
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-533017000	usd
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-235081000	usd
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-46794000	usd
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	25726000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	-6667000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	0	usd
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	0	usd
CY2022	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	-1674000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	-993000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	489000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-240074000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-45801000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	25237000	usd
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-60922000	usd
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-11937000	usd
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	6471000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent	-1789000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent	0	usd
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent	0	usd
CY2022	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	-446000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	-250000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	112000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-62265000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-11687000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	6359000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-177809000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-34114000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	18878000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-85276000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	84550000	usd
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-514139000	usd
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	1758564000	usd
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-533017000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	18878000	usd
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-514139000	usd
CY2020	us-gaap	Stock Issued During Period Value Conversion Of Convertible Securities StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	0	usd
CY2020	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.72
CY2020	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	36251000	usd
CY2020	us-gaap	Preferred Stock Dividends Per Share Declared PreferredStockDividendsPerShareDeclared	1.20
CY2020	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	313000	usd
CY2020	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	473000	usd
CY2020	us-gaap	Stock Issued During Period Value Restricted Stock Award Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures	0	usd
CY2020	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	664000	usd
CY2020	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	usd
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	4727000	usd
CY2020	us-gaap	Stockholders Equity Other StockholdersEquityOther	626000	usd
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	1187773000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	118664000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-34114000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	84550000	usd
CY2021	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.48
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	24553000	usd
CY2021	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	68712000	usd
CY2021	us-gaap	Stock Issued During Period Value Restricted Stock Award Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures	0	usd
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	417000	usd
CY2021	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	usd
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	4170000	usd
CY2021	us-gaap	Stockholders Equity Other StockholdersEquityOther	1210000	usd
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	1182435000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	92533000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-177809000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-85276000	usd
CY2022	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.54
CY2022	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	24527000	usd
CY2022	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	124519000	usd
CY2022	us-gaap	Stock Issued During Period Value Restricted Stock Award Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures	0	usd
CY2022	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	270000	usd
CY2022	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	usd
CY2022	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	7338000	usd
CY2022	us-gaap	Stockholders Equity Other StockholdersEquityOther	1659000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	954062000	usd
CY2022	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	92533000	usd
CY2021	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	118664000	usd
CY2020	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-513175000	usd
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	0	usd
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	0	usd
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-19842000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	92533000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	118664000	usd
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-533017000	usd
CY2022	bhlb	Financing Receivable And Debt Securities Held To Maturity Credit Loss Expense Reversal FinancingReceivableAndDebtSecuritiesHeldToMaturityCreditLossExpenseReversal	11000000	usd
CY2021	bhlb	Financing Receivable And Debt Securities Held To Maturity Credit Loss Expense Reversal FinancingReceivableAndDebtSecuritiesHeldToMaturityCreditLossExpenseReversal	-500000	usd
CY2020	bhlb	Financing Receivable And Debt Securities Held To Maturity Credit Loss Expense Reversal FinancingReceivableAndDebtSecuritiesHeldToMaturityCreditLossExpenseReversal	75878000	usd
CY2022	bhlb	Amortization Of Securities AmortizationOfSecurities	2886000	usd
CY2021	bhlb	Amortization Of Securities AmortizationOfSecurities	1939000	usd
CY2020	bhlb	Amortization Of Securities AmortizationOfSecurities	2513000	usd
CY2022	bhlb	Change In Unamortized Net Loan Costs And Premiums ChangeInUnamortizedNetLoanCostsAndPremiums	-3312000	usd
CY2021	bhlb	Change In Unamortized Net Loan Costs And Premiums ChangeInUnamortizedNetLoanCostsAndPremiums	1918000	usd
CY2020	bhlb	Change In Unamortized Net Loan Costs And Premiums ChangeInUnamortizedNetLoanCostsAndPremiums	-21856000	usd
CY2022	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	9576000	usd
CY2021	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	11035000	usd
CY2020	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	11919000	usd
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	7338000	usd
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	4170000	usd
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	4727000	usd
CY2022	bhlb	Accretion Of Purchase Accounting Entries AccretionOfPurchaseAccountingEntries	-1637000	usd
CY2021	bhlb	Accretion Of Purchase Accounting Entries AccretionOfPurchaseAccountingEntries	-6577000	usd
CY2020	bhlb	Accretion Of Purchase Accounting Entries AccretionOfPurchaseAccountingEntries	-10377000	usd
CY2022	us-gaap	Adjustment For Amortization AdjustmentForAmortization	5134000	usd
CY2021	us-gaap	Adjustment For Amortization AdjustmentForAmortization	5200000	usd
CY2020	us-gaap	Adjustment For Amortization AdjustmentForAmortization	6181000	usd
CY2022	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	5540000	usd
CY2021	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	5561000	usd
CY2020	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	5354000	usd
CY2022	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	-2031000	usd
CY2021	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	-787000	usd
CY2020	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	-7576000	usd
CY2022	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	-5168000	usd
CY2021	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	-5775000	usd
CY2020	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	4267000	usd
CY2022	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	0	usd
CY2021	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-2811000	usd
CY2020	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-327000	usd
CY2022	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	0	usd
CY2021	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-6000	usd
CY2020	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-13000	usd
CY2022	bhlb	Amortization Of Tax Credits AmortizationOfTaxCredits	3508000	usd
CY2021	bhlb	Amortization Of Tax Credits AmortizationOfTaxCredits	3444000	usd
CY2020	bhlb	Amortization Of Tax Credits AmortizationOfTaxCredits	3645000	usd
CY2022	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2021	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2020	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	553762000	usd
CY2022	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	usd
CY2021	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	52942000	usd
CY2020	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	usd
CY2022	us-gaap	Federal Home Loan Bank Advances General Debt Obligations Disclosures Repayment And Penalties FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresRepaymentAndPenalties	0	usd
CY2021	us-gaap	Federal Home Loan Bank Advances General Debt Obligations Disclosures Repayment And Penalties FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresRepaymentAndPenalties	862000	usd
CY2020	us-gaap	Federal Home Loan Bank Advances General Debt Obligations Disclosures Repayment And Penalties FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresRepaymentAndPenalties	0	usd
CY2022	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	12076000	usd
CY2021	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-18282000	usd
CY2020	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	31247000	usd
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	123233000	usd
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	105477000	usd
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	123977000	usd
CY2022	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	0	usd
CY2021	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	0	usd
CY2020	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	103664000	usd
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	123233000	usd
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	105477000	usd
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	227641000	usd
CY2022	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-818000	usd
CY2021	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-776000	usd
CY2020	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-734000	usd
CY2022	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	0	usd
CY2021	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	0	usd
CY2020	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	17631000	usd
CY2022	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	0	usd
CY2021	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	2880000	usd
CY2020	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	33928000	usd
CY2022	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	478940000	usd
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	804616000	usd
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	885182000	usd
CY2022	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	149994000	usd
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	0	usd
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	69337000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	548423000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	575538000	usd
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	457586000	usd
CY2022	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	807000	usd
CY2021	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	219470000	usd
CY2020	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	144651000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	51961000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	46061000	usd
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	35331000	usd
CY2022	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	1559012000	usd
CY2021	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-1262521000	usd
CY2020	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-1054029000	usd
CY2022	bhlb	Increase Decrease In Loans Held For Sale Investing Activities IncreaseDecreaseInLoansHeldForSaleInvestingActivities	0	usd
CY2021	bhlb	Increase Decrease In Loans Held For Sale Investing Activities IncreaseDecreaseInLoansHeldForSaleInvestingActivities	-50914000	usd
CY2020	bhlb	Increase Decrease In Loans Held For Sale Investing Activities IncreaseDecreaseInLoansHeldForSaleInvestingActivities	0	usd
CY2022	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	2311000	usd
CY2021	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	2566000	usd
CY2020	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	553000	usd
CY2022	us-gaap	Payments To Acquire Federal Reserve Stock PaymentsToAcquireFederalReserveStock	124331000	usd
CY2021	us-gaap	Payments To Acquire Federal Reserve Stock PaymentsToAcquireFederalReserveStock	0	usd
CY2020	us-gaap	Payments To Acquire Federal Reserve Stock PaymentsToAcquireFederalReserveStock	6741000	usd
CY2022	us-gaap	Proceeds From Sale Of Federal Reserve Stock ProceedsFromSaleOfFederalReserveStock	127912000	usd
CY2021	us-gaap	Proceeds From Sale Of Federal Reserve Stock ProceedsFromSaleOfFederalReserveStock	24078000	usd
CY2020	us-gaap	Proceeds From Sale Of Federal Reserve Stock ProceedsFromSaleOfFederalReserveStock	19887000	usd
CY2022	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	14537000	usd
CY2021	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	2878000	usd
CY2020	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	7280000	usd
CY2022	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1495000	usd
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1606000	usd
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	7208000	usd
CY2022	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	24323000	usd
CY2021	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	16417000	usd
CY2020	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	37988000	usd
CY2022	us-gaap	Proceeds From Sale Of Other Real Estate ProceedsFromSaleOfOtherRealEstate	0	usd
CY2021	us-gaap	Proceeds From Sale Of Other Real Estate ProceedsFromSaleOfOtherRealEstate	187000	usd
CY2020	us-gaap	Proceeds From Sale Of Other Real Estate ProceedsFromSaleOfOtherRealEstate	171000	usd
CY2022	bhlb	Payments For Disposal Of Business Settlement Amount PaymentsForDisposalOfBusinessSettlementAmount	0	usd
CY2021	bhlb	Payments For Disposal Of Business Settlement Amount PaymentsForDisposalOfBusinessSettlementAmount	352814000	usd
CY2020	bhlb	Payments For Disposal Of Business Settlement Amount PaymentsForDisposalOfBusinessSettlementAmount	0	usd
CY2022	us-gaap	Cash Provided By Used In Investing Activities Discontinued Operations CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations	0	usd
CY2021	us-gaap	Cash Provided By Used In Investing Activities Discontinued Operations CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations	0	usd
CY2020	us-gaap	Cash Provided By Used In Investing Activities Discontinued Operations CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations	252000	usd
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1273380000	usd
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	600554000	usd
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	641103000	usd
CY2022	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	258316000	usd
CY2021	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	-154052000	usd
CY2020	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	499657000	usd
CY2022	bhlb	Increase Decrease In Loans Held For Sale Financing Activities IncreaseDecreaseInLoansHeldForSaleFinancingActivities	0	usd
CY2021	bhlb	Increase Decrease In Loans Held For Sale Financing Activities IncreaseDecreaseInLoansHeldForSaleFinancingActivities	-20953000	usd
CY2020	bhlb	Increase Decrease In Loans Held For Sale Financing Activities IncreaseDecreaseInLoansHeldForSaleFinancingActivities	0	usd
CY2022	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	51275000	usd
CY2021	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	0	usd
CY2020	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	326277000	usd
CY2022	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	60196000	usd
CY2021	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	462059000	usd
CY2020	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	582648000	usd
CY2022	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	98032000	usd
CY2021	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	0	usd
CY2020	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	0	usd
CY2022	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	75000000	usd
CY2021	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	usd
CY2020	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	usd
CY2022	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	124519000	usd
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	68712000	usd
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	473000	usd
CY2022	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	270000	usd
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	417000	usd
CY2020	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	664000	usd
CY2022	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	24527000	usd
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	24553000	usd
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	36564000	usd
CY2022	bhlb	Settlementof Derivative Contractswith Institutional Counterparties SettlementofDerivativeContractswithInstitutionalCounterparties	-84044000	usd
CY2021	bhlb	Settlementof Derivative Contractswith Institutional Counterparties SettlementofDerivativeContractswithInstitutionalCounterparties	-51907000	usd
CY2020	bhlb	Settlementof Derivative Contractswith Institutional Counterparties SettlementofDerivativeContractswithInstitutionalCounterparties	97611000	usd
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	207695000	usd
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-636099000	usd
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	109302000	usd
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-942452000	usd
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	69932000	usd
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	978046000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	1627807000	usd
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	1557875000	usd
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	579829000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	685355000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	1627807000	usd
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	1557875000	usd
CY2022	bhlb	Interest Paid On Deposits InterestPaidOnDeposits	32782000	usd
CY2021	bhlb	Interest Paid On Deposits InterestPaidOnDeposits	29606000	usd
CY2020	bhlb	Interest Paid On Deposits InterestPaidOnDeposits	82319000	usd
CY2022	us-gaap	Interest Paid Net InterestPaidNet	9043000	usd
CY2021	us-gaap	Interest Paid Net InterestPaidNet	11385000	usd
CY2020	us-gaap	Interest Paid Net InterestPaidNet	21277000	usd
CY2022	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	28439000	usd
CY2021	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	14816000	usd
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	-13864000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-177809000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-34114000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	18878000	usd
CY2022	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	3369000	usd
CY2021	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	11660000	usd
CY2020	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	14845000	usd
CY2022	us-gaap	Transfer Of Loans Held For Sale To Portfolio Loans1 TransferOfLoansHeldForSaleToPortfolioLoans1	606000	usd
CY2021	us-gaap	Transfer Of Loans Held For Sale To Portfolio Loans1 TransferOfLoansHeldForSaleToPortfolioLoans1	0	usd
CY2020	us-gaap	Transfer Of Loans Held For Sale To Portfolio Loans1 TransferOfLoansHeldForSaleToPortfolioLoans1	0	usd
CY2022	bhlb	Noncash Investing And Financing Activities Reclassification Of Premises And Equipment To Held For Sale NoncashInvestingAndFinancingActivitiesReclassificationOfPremisesAndEquipmentToHeldForSale	1380000	usd
CY2021	bhlb	Noncash Investing And Financing Activities Reclassification Of Premises And Equipment To Held For Sale NoncashInvestingAndFinancingActivitiesReclassificationOfPremisesAndEquipmentToHeldForSale	4577000	usd
CY2020	bhlb	Noncash Investing And Financing Activities Reclassification Of Premises And Equipment To Held For Sale NoncashInvestingAndFinancingActivitiesReclassificationOfPremisesAndEquipmentToHeldForSale	0	usd
CY2022	bhlb	Real Estate Owned Acquired In Settlement Of Loans RealEstateOwnedAcquiredInSettlementOfLoans	0	usd
CY2021	bhlb	Real Estate Owned Acquired In Settlement Of Loans RealEstateOwnedAcquiredInSettlementOfLoans	0	usd
CY2020	bhlb	Real Estate Owned Acquired In Settlement Of Loans RealEstateOwnedAcquiredInSettlementOfLoans	224000	usd
CY2022	bhlb	Noncash Investing And Financing Activities Premium Payable On Cash Flow Hedges NoncashInvestingAndFinancingActivitiesPremiumPayableOnCashFlowHedges	2296000	usd
CY2021	bhlb	Noncash Investing And Financing Activities Premium Payable On Cash Flow Hedges NoncashInvestingAndFinancingActivitiesPremiumPayableOnCashFlowHedges	0	usd
CY2020	bhlb	Noncash Investing And Financing Activities Premium Payable On Cash Flow Hedges NoncashInvestingAndFinancingActivitiesPremiumPayableOnCashFlowHedges	0	usd
CY2022	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	<div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-style:italic;font-weight:700;line-height:120%">Reclassifications</span></div><div style="margin-top:2.7pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-weight:400;line-height:120%">Certain items in prior financial statements have been reclassified to conform to the current presentation.</span></div>
CY2022	us-gaap	Use Of Estimates UseOfEstimates	<div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-style:italic;font-weight:700;line-height:120%">Use of Estimates</span></div><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-weight:400;line-height:120%">The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the financial statements. Actual results could differ from those estimates.</span></div><div><span><br/></span></div><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:11pt;font-weight:400;line-height:120%">Refer to Note 17 – Other Commitments, Contingencies, and Off-Balance Sheet Activities for pandemic related risks and uncertainties.</span></div>
CY2022	bhlb	Threshold Period Past Due For Financing Receivable Excluding Automobile Loans Not Accrue Interest ThresholdPeriodPastDueForFinancingReceivableExcludingAutomobileLoansNotAccrueInterest	P90D
CY2022	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	1	segment
CY2022	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	1	segment
CY2021Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	0	usd
CY2022Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	0	usd
CY2022Q4	us-gaap	Trading Securities Debt Amortized Cost TradingSecuritiesDebtAmortizedCost	7100000	usd
CY2021Q4	us-gaap	Trading Securities Debt Amortized Cost TradingSecuritiesDebtAmortizedCost	7900000	usd
CY2022Q4	us-gaap	Trading Securities TradingSecurities	6700000	usd
CY2021Q4	us-gaap	Trading Securities TradingSecurities	8400000	usd
CY2022	us-gaap	Debt Securities Trading Unrealized Gain Loss DebtSecuritiesTradingUnrealizedGainLoss	-800000	usd
CY2021	us-gaap	Debt Securities Trading Unrealized Gain Loss DebtSecuritiesTradingUnrealizedGainLoss	-600000	usd
CY2020	us-gaap	Debt Securities Trading Unrealized Gain Loss DebtSecuritiesTradingUnrealizedGainLoss	-300000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	1661196000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	571000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	238567000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	1423200000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	583453000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	699000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	76688000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	507464000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	91000	usd
CY2022Q4	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	15035000	usd
CY2022	us-gaap	Equity Securities Fv Ni Unrealized Gain EquitySecuritiesFvNiUnrealizedGain	0	usd
CY2022	us-gaap	Equity Securities Fv Ni Unrealized Loss EquitySecuritiesFvNiUnrealizedLoss	2179000	usd
CY2022Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	12856000	usd
CY2022Q4	bhlb	Debt Securities Available For Sale And Held To Maturity And Equity Securities Fvni Amortized Cost Excluding Accrued Interest DebtSecuritiesAvailableForSaleAndHeldToMaturityAndEquitySecuritiesFVNIAmortizedCostExcludingAccruedInterest	2259684000	usd
CY2022Q4	bhlb	Debt Securities Availableforsaleand Heldtomaturityand Equity Securities Fvni Accumulated Gross Unrealized Gainbefore Tax DebtSecuritiesAvailableforsaleandHeldtomaturityandEquitySecuritiesFVNIAccumulatedGrossUnrealizedGainbeforeTax	1270000	usd
CY2022Q4	bhlb	Debt Securities Availableforsaleand Heldtomaturityand Equity Securities Fvni Accumulated Gross Unrealized Lossbefore Tax DebtSecuritiesAvailableforsaleandHeldtomaturityandEquitySecuritiesFVNIAccumulatedGrossUnrealizedLossbeforeTax	317434000	usd
CY2022Q4	bhlb	Debt Securities Available For Sale And Held To Maturity And Equity Securities Fvni Excluding Accrued Interest DebtSecuritiesAvailableForSaleAndHeldToMaturityAndEquitySecuritiesFVNIExcludingAccruedInterest	1943520000	usd
CY2022Q4	bhlb	Debt Securities Available For Sale And Held To Maturity Allowance For Credit Losses Excluding Accrued Interest DebtSecuritiesAvailableForSaleAndHeldToMaturityAllowanceForCreditLossesExcludingAccruedInterest	91000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	1881813000	usd
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	18168000	usd
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	22396000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	1877585000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2021Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	636503000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	19741000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	9008000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	647236000	usd
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	105000	usd
CY2021Q4	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	15689000	usd
CY2021	us-gaap	Equity Securities Fv Ni Unrealized Gain EquitySecuritiesFvNiUnrealizedGain	67000	usd
CY2021	us-gaap	Equity Securities Fv Ni Unrealized Loss EquitySecuritiesFvNiUnrealizedLoss	303000	usd
CY2021Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	15453000	usd
CY2021Q4	bhlb	Debt Securities Available For Sale And Held To Maturity And Equity Securities Fvni Amortized Cost Excluding Accrued Interest DebtSecuritiesAvailableForSaleAndHeldToMaturityAndEquitySecuritiesFVNIAmortizedCostExcludingAccruedInterest	2534005000	usd
CY2021Q4	bhlb	Debt Securities Availableforsaleand Heldtomaturityand Equity Securities Fvni Accumulated Gross Unrealized Gainbefore Tax DebtSecuritiesAvailableforsaleandHeldtomaturityandEquitySecuritiesFVNIAccumulatedGrossUnrealizedGainbeforeTax	37976000	usd
CY2021Q4	bhlb	Debt Securities Availableforsaleand Heldtomaturityand Equity Securities Fvni Accumulated Gross Unrealized Lossbefore Tax DebtSecuritiesAvailableforsaleandHeldtomaturityandEquitySecuritiesFVNIAccumulatedGrossUnrealizedLossbeforeTax	31707000	usd
CY2021Q4	bhlb	Debt Securities Available For Sale And Held To Maturity And Equity Securities Fvni Excluding Accrued Interest DebtSecuritiesAvailableForSaleAndHeldToMaturityAndEquitySecuritiesFVNIExcludingAccruedInterest	2540274000	usd
CY2021Q4	bhlb	Debt Securities Available For Sale And Held To Maturity Allowance For Credit Losses Excluding Accrued Interest DebtSecuritiesAvailableForSaleAndHeldToMaturityAllowanceForCreditLossesExcludingAccruedInterest	105000	usd
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	105000	usd
CY2022	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	14000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	91000	usd
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	104000	usd
CY2021	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	-1000	usd
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	105000	usd
CY2019Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2020	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	205000	usd
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	104000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	12482000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	12482000	usd
CY2022Q4	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	995000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	995000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	11254000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	11269000	usd
CY2022Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	2191000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	2181000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	49729000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	46904000	usd
CY2022Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost	28544000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	28543000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	48473000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	45819000	usd
CY2022Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling After Ten Years Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost	237423000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	214308000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	121938000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	116474000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Amortized Cost Basis HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	269153000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue	246027000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	1539258000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	1306726000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount	314300000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	261437000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	1661196000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	1423200000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	583453000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	507464000	usd
CY2022Q4	bhlb	Security Owned And Pledged As Collateral For Interest Rate Swap Amortized Cost SecurityOwnedAndPledgedAsCollateralForInterestRateSwapAmortizedCost	11972000	usd
CY2022Q4	bhlb	Security Owned And Pledged As Collateral For Interest Rate Swap Fair Value SecurityOwnedAndPledgedAsCollateralForInterestRateSwapFairValue	11973000	usd
CY2021Q4	bhlb	Security Owned And Pledged As Collateral For Interest Rate Swap Amortized Cost SecurityOwnedAndPledgedAsCollateralForInterestRateSwapAmortizedCost	34773000	usd
CY2021Q4	bhlb	Security Owned And Pledged As Collateral For Interest Rate Swap Fair Value SecurityOwnedAndPledgedAsCollateralForInterestRateSwapFairValue	34896000	usd
CY2022Q4	bhlb	Security Owned And Pledged As Collateral For Municipal Deposits Amortized Cost SecurityOwnedAndPledgedAsCollateralForMunicipalDepositsAmortizedCost	304741000	usd
CY2022Q4	bhlb	Security Owned And Pledged As Collateral For Municipal Deposits Fair Value SecurityOwnedAndPledgedAsCollateralForMunicipalDepositsFairValue	276804000	usd
CY2021Q4	bhlb	Security Owned And Pledged As Collateral For Municipal Deposits Amortized Cost SecurityOwnedAndPledgedAsCollateralForMunicipalDepositsAmortizedCost	183408000	usd
CY2021Q4	bhlb	Security Owned And Pledged As Collateral For Municipal Deposits Fair Value SecurityOwnedAndPledgedAsCollateralForMunicipalDepositsFairValue	189535000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-442000	usd
CY2022Q4	bhlb	Security Owned And Pledged As Collateral Amortized Cost SecurityOwnedAndPledgedAsCollateralAmortizedCost	316713000	usd
CY2022Q4	us-gaap	Security Owned And Pledged As Collateral Associated Liabilities Fair Value SecurityOwnedAndPledgedAsCollateralAssociatedLiabilitiesFairValue	288777000	usd
CY2021Q4	bhlb	Security Owned And Pledged As Collateral Amortized Cost SecurityOwnedAndPledgedAsCollateralAmortizedCost	218181000	usd
CY2021Q4	us-gaap	Security Owned And Pledged As Collateral Associated Liabilities Fair Value SecurityOwnedAndPledgedAsCollateralAssociatedLiabilitiesFairValue	224431000	usd
CY2022	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	150000000	usd
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	0	usd
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	69000000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	72000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	108000	usd
CY2020	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	4602000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	2009000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	550000	usd
CY2020	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	11133000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-1937000	usd
CY2020	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-6531000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	40176000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	443798000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	198391000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	938147000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	238567000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	1381945000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	8958000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	187307000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	67730000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	239115000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	76688000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	426422000	usd
CY2022Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position Lessthan12 Months Aggregate Losses DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPositionLessthan12MonthsAggregateLosses	49134000	usd
CY2022Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position Lessthan Twelve Months Fair Value DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPositionLessthanTwelveMonthsFairValue	631105000	usd
CY2022Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position12 Monthsor Longer Aggregate Losses DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPosition12MonthsorLongerAggregateLosses	266121000	usd
CY2022Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position Twelve Monthsor Longer Fair Value DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsorLongerFairValue	1177262000	usd
CY2022Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position Aggregate Losses DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses	315255000	usd
CY2022Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position Fair Value DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPositionFairValue	1808367000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	14528000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	712488000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	7868000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	252279000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	22396000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	964767000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	4610000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	194606000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	4398000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	113891000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	9008000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	308497000	usd
CY2021Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position Lessthan12 Months Aggregate Losses DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPositionLessthan12MonthsAggregateLosses	19138000	usd
CY2021Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position Lessthan Twelve Months Fair Value DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPositionLessthanTwelveMonthsFairValue	907094000	usd
CY2021Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position12 Monthsor Longer Aggregate Losses DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPosition12MonthsorLongerAggregateLosses	12266000	usd
CY2021Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position Twelve Monthsor Longer Fair Value DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsorLongerFairValue	366170000	usd
CY2021Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position Aggregate Losses DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses	31404000	usd
CY2021Q4	bhlb	Debt Securities Heldto Maturityand Availablefor Sale Securities Continuous Unrealized Loss Position Fair Value DebtSecuritiesHeldtoMaturityandAvailableforSaleSecuritiesContinuousUnrealizedLossPositionFairValue	1273264000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	8335309000	usd
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	6825847000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	96270000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	106094000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	8239039000	usd
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	6719753000	usd
CY2022	us-gaap	Payments To Acquire Loans And Leases Held For Investment PaymentsToAcquireLoansAndLeasesHeldForInvestment	718000000	usd
CY2022	us-gaap	Proceeds From Sale Of Loans And Leases Held For Investment ProceedsFromSaleOfLoansAndLeasesHeldForInvestment	366000000	usd
CY2021	us-gaap	Payments To Acquire Loans And Leases Held For Investment PaymentsToAcquireLoansAndLeasesHeldForInvestment	211000000	usd
CY2021	us-gaap	Proceeds From Sale Of Loans And Leases Held For Investment ProceedsFromSaleOfLoansAndLeasesHeldForInvestment	560000000	usd
CY2020	us-gaap	Payments To Acquire Loans And Leases Held For Investment PaymentsToAcquireLoansAndLeasesHeldForInvestment	98000000	usd
CY2020	us-gaap	Proceeds From Sale Of Loans And Leases Held For Investment ProceedsFromSaleOfLoansAndLeasesHeldForInvestment	415000000	usd
CY2022	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	12500000	usd
CY2021	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	20700000	usd
CY2020	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	10600000	usd
CY2022Q4	us-gaap	Due To Related Parties Current And Noncurrent DueToRelatedPartiesCurrentAndNoncurrent	1500000	usd
CY2021Q4	us-gaap	Due To Related Parties Current And Noncurrent DueToRelatedPartiesCurrentAndNoncurrent	1700000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	800000	usd
CY2021Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	1000000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	106094000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	28058000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	7220000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	11014000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	96270000	usd
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	127302000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	31018000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	10311000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	-501000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	106094000	usd
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	63575000	usd
CY2020	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	45795000	usd
CY2020	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	8005000	usd
CY2020	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	76083000	usd
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	127302000	usd
CY2021Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	7043000	usd
CY2022	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	1545000	usd
CY2022Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	8588000	usd
CY2020Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	7629000	usd
CY2021	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	-586000	usd
CY2021Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	7043000	usd
CY2019Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	100000	usd
CY2020	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	-464000	usd
CY2020Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	7629000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	8335309000	usd
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	6825847000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual FinancingReceivableExcludingAccruedInterestNonaccrual	31114000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual No Allowance FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance	21404000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest90 Days Or More Past Due Still Accruing FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing	7038000	usd
CY2022	us-gaap	Financing Receivable Nonaccrual Interest Income FinancingReceivableNonaccrualInterestIncome	0	usd
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual FinancingReceivableExcludingAccruedInterestNonaccrual	35326000	usd
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual No Allowance FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance	19174000	usd
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest90 Days Or More Past Due Still Accruing FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing	3271000	usd
CY2021	us-gaap	Financing Receivable Nonaccrual Interest Income FinancingReceivableNonaccrualInterestIncome	0	usd
CY2021Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	27102000	usd
CY2022	bhlb	Financing Receivable Troubled Debt Restructuring Principal Payments FinancingReceivableTroubledDebtRestructuringPrincipalPayments	1221000	usd
CY2022	bhlb	Financing Receivable Troubled Debt Restructuring Status Change FinancingReceivableTroubledDebtRestructuringStatusChange	0	usd
CY2022	bhlb	Financing Receivable Troubled Debt Restructuring Other Increase Decrease FinancingReceivableTroubledDebtRestructuringOtherIncreaseDecrease	-18465000	usd
CY2022	bhlb	Financing Receivable Troubled Debt Restructuring Additions FinancingReceivableTroubledDebtRestructuringAdditions	4944000	usd
CY2022Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	12360000	usd
CY2020Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	20548000	usd
CY2021	bhlb	Financing Receivable Troubled Debt Restructuring Principal Payments FinancingReceivableTroubledDebtRestructuringPrincipalPayments	18878000	usd
CY2021	bhlb	Financing Receivable Troubled Debt Restructuring Status Change FinancingReceivableTroubledDebtRestructuringStatusChange	0	usd
CY2021	bhlb	Financing Receivable Troubled Debt Restructuring Other Increase Decrease FinancingReceivableTroubledDebtRestructuringOtherIncreaseDecrease	-1327000	usd
CY2021	bhlb	Financing Receivable Troubled Debt Restructuring Additions FinancingReceivableTroubledDebtRestructuringAdditions	26759000	usd
CY2021Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	27102000	usd
CY2022	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	93000	loan
CY2022	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	4944000	usd
CY2022	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	4944000	usd
CY2021	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	18000	loan
CY2021	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	26759000	usd
CY2021	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	26759000	usd
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	16000	loan
CY2020	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	12197000	usd
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	12197000	usd
CY2022	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	2	loan
CY2021	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	4	loan
CY2020	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	loan
CY2022	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	2	loan
CY2022	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	115000	usd
CY2021	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	4	loan
CY2021	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	18817000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	180214000	usd
CY2021Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	183236000	usd
CY2022Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	94997000	usd
CY2021Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	88853000	usd
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	9600000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	4600000	usd
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	11000000	usd
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	12500000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	85079000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	60596000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	24483000	usd
CY2021Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	85079000	usd
CY2021Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	55460000	usd
CY2021Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	29619000	usd
CY2022	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5100000	usd
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5200000	usd
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6200000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	4800000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	4500000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	4500000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	3600000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	2500000	usd
CY2020	us-gaap	Impairment Of Intangible Assets Finitelived ImpairmentOfIntangibleAssetsFinitelived	0	usd
CY2021	us-gaap	Impairment Of Intangible Assets Finitelived ImpairmentOfIntangibleAssetsFinitelived	0	usd
CY2022	us-gaap	Impairment Of Intangible Assets Finitelived ImpairmentOfIntangibleAssetsFinitelived	0	usd
CY2022Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	13047000	usd
CY2021Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	16022000	usd
CY2022Q4	us-gaap	Interest Receivable InterestReceivable	46868000	usd
CY2021Q4	us-gaap	Interest Receivable InterestReceivable	33534000	usd
CY2022Q4	us-gaap	Income Tax Receivable IncomeTaxReceivable	34386000	usd
CY2021Q4	us-gaap	Income Tax Receivable IncomeTaxReceivable	30614000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	46411000	usd
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	52180000	usd
CY2022Q4	us-gaap	Derivative Assets DerivativeAssets	54241000	usd
CY2021Q4	us-gaap	Derivative Assets DerivativeAssets	79528000	usd
CY2022Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	118331000	usd
CY2021Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	52620000	usd
CY2022Q4	us-gaap	Other Assets Miscellaneous OtherAssetsMiscellaneous	35651000	usd
CY2021Q4	us-gaap	Other Assets Miscellaneous OtherAssetsMiscellaneous	23886000	usd
CY2022Q4	us-gaap	Other Assets OtherAssets	348935000	usd
CY2021Q4	us-gaap	Other Assets OtherAssets	288384000	usd
CY2021Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	16022000	usd
CY2020Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	16348000	usd
CY2019Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	26451000	usd
CY2022	us-gaap	Servicing Asset At Amortized Value Additions ServicingAssetAtAmortizedValueAdditions	3119000	usd
CY2021	us-gaap	Servicing Asset At Amortized Value Additions ServicingAssetAtAmortizedValueAdditions	4568000	usd
CY2020	us-gaap	Servicing Asset At Amortized Value Additions ServicingAssetAtAmortizedValueAdditions	3875000	usd
CY2022	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	4590000	usd
CY2021	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	4921000	usd
CY2020	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	3761000	usd
CY2022	us-gaap	Servicing Asset At Amortized Value Disposals ServicingAssetAtAmortizedValueDisposals	958000	usd
CY2021	us-gaap	Servicing Asset At Amortized Value Disposals ServicingAssetAtAmortizedValueDisposals	0	usd
CY2020	us-gaap	Servicing Asset At Amortized Value Disposals ServicingAssetAtAmortizedValueDisposals	0	usd
CY2022	us-gaap	Servicing Asset At Amortized Value Valuation Allowance ServicingAssetAtAmortizedValueValuationAllowance	-546000	usd
CY2021	us-gaap	Servicing Asset At Amortized Value Valuation Allowance ServicingAssetAtAmortizedValueValuationAllowance	27000	usd
CY2020	us-gaap	Servicing Asset At Amortized Value Valuation Allowance ServicingAssetAtAmortizedValueValuationAllowance	-10217000	usd
CY2022Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	13047000	usd
CY2021Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	16022000	usd
CY2020Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	16348000	usd
CY2022Q4	bhlb	Servicing Asset Portion Reported At Fair Value ServicingAssetPortionReportedAtFairValue	1800000	usd
CY2021Q4	bhlb	Servicing Asset Portion Reported At Fair Value ServicingAssetPortionReportedAtFairValue	2000000	usd
CY2022Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	16700000	usd
CY2021Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	16600000	usd
CY2022Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	912756000	usd
CY2021Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	1228874000	usd
CY2022Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	606856000	usd
CY2021Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	280403000	usd
CY2022Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	68984000	usd
CY2021Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	81391000	usd
CY2022Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	28441000	usd
CY2021Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	52000000	usd
CY2022Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	15835000	usd
CY2021Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	34605000	usd
CY2022Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	835000	usd
CY2021Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	1667000	usd
CY2022Q4	us-gaap	Time Deposits TimeDeposits	1633707000	usd
CY2021Q4	us-gaap	Time Deposits TimeDeposits	1678940000	usd
CY2022Q4	us-gaap	Time Deposits Less Than100000 TimeDepositsLessThan100000	549265000	usd
CY2021Q4	us-gaap	Time Deposits Less Than100000 TimeDepositsLessThan100000	676979000	usd
CY2022Q4	bhlb	Time Deposits100000 Through250000 TimeDeposits100000Through250000	642600000	usd
CY2021Q4	bhlb	Time Deposits100000 Through250000 TimeDeposits100000Through250000	610174000	usd
CY2022Q4	bhlb	Time Deposits250000 Or More TimeDeposits250000OrMore	441842000	usd
CY2021Q4	bhlb	Time Deposits250000 Or More TimeDeposits250000OrMore	391787000	usd
CY2022Q4	us-gaap	Time Deposits TimeDeposits	1633707000	usd
CY2021Q4	us-gaap	Time Deposits TimeDeposits	1678940000	usd
CY2022Q4	bhlb	Brokered Time Deposits BrokeredTimeDeposits	120900000	usd
CY2021Q4	bhlb	Brokered Time Deposits BrokeredTimeDeposits	228100000	usd
CY2022Q4	bhlb	Reciprocal Money Market Deposits ReciprocalMoneyMarketDeposits	71100000	usd
CY2021Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	110844000	usd
CY2021Q4	bhlb	Reciprocal Money Market Deposits ReciprocalMoneyMarketDeposits	89200000	usd
CY2022Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	0	usd
CY2022Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0
CY2021Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	0	usd
CY2021Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0
CY2022Q4	us-gaap	Long Term Debt LongTermDebt	125509000	usd
CY2022Q4	us-gaap	Longterm Debt Weighted Average Interest Rate LongtermDebtWeightedAverageInterestRate	0.0552
CY2021Q4	us-gaap	Long Term Debt LongTermDebt	110844000	usd
CY2021Q4	us-gaap	Longterm Debt Weighted Average Interest Rate LongtermDebtWeightedAverageInterestRate	0.0533
CY2022Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	125509000	usd
CY2022Q4	us-gaap	Debt Weighted Average Interest Rate DebtWeightedAverageInterestRate	0.0552
CY2021Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	9862000	usd
CY2021Q4	us-gaap	Debt Weighted Average Interest Rate DebtWeightedAverageInterestRate	0.0533
CY2022Q4	us-gaap	Advances From Federal Home Loan Banks AdvancesFromFederalHomeLoanBanks	4445000	usd
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary By Interest Rate Type Floating Rate FederalHomeLoanBankAdvancesMaturitiesSummaryByInterestRateTypeFloatingRate	0	usd
CY2022Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary By Interest Rate Type Floating Rate FederalHomeLoanBankAdvancesMaturitiesSummaryByInterestRateTypeFloatingRate	0	usd
CY2022Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	97030000	usd
CY2021Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	35194000	usd
CY2022Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	9306000	usd
CY2022Q4	us-gaap	Pension And Other Postretirement And Postemployment Benefit Plans Liabilities Current And Noncurrent PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrentAndNoncurrent	45175000	usd
CY2021Q4	us-gaap	Pension And Other Postretirement And Postemployment Benefit Plans Liabilities Current And Noncurrent PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrentAndNoncurrent	45498000	usd
CY2022Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	53736000	usd
CY2021Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	55674000	usd
CY2022Q4	us-gaap	Interest Payable Current And Noncurrent InterestPayableCurrentAndNoncurrent	1610000	usd
CY2021Q4	us-gaap	Interest Payable Current And Noncurrent InterestPayableCurrentAndNoncurrent	775000	usd
CY2022Q4	bhlb	Customer Transaction Clearing Accounts Payable CustomerTransactionClearingAccountsPayable	5758000	usd
CY2021Q4	bhlb	Customer Transaction Clearing Accounts Payable CustomerTransactionClearingAccountsPayable	5718000	usd
CY2022Q4	us-gaap	Other Sundry Liabilities OtherSundryLiabilities	43409000	usd
CY2021Q4	us-gaap	Other Sundry Liabilities OtherSundryLiabilities	39960000	usd
CY2022Q4	us-gaap	Other Liabilities OtherLiabilities	256024000	usd
CY2021Q4	us-gaap	Other Liabilities OtherLiabilities	192681000	usd
CY2022	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	2900000	usd
CY2021	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	3200000	usd
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	3500000	usd
CY2022Q4	bhlb	Postemployment Benefits Liability Split Dollar Agreement PostemploymentBenefitsLiabilitySplitDollarAgreement	7900000	usd
CY2021Q4	bhlb	Postemployment Benefits Liability Split Dollar Agreement PostemploymentBenefitsLiabilitySplitDollarAgreement	7800000	usd
CY2022	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	17915000	usd
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	17340000	usd
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-19889000	usd
CY2022	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	6831000	usd
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	7580000	usd
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	-3976000	usd
CY2022	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	24746000	usd
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	24920000	usd
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	-23865000	usd
CY2022	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-2274000	usd
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	5125000	usd
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	2048000	usd
CY2022	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-1187000	usd
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	112000	usd
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1964000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-3461000	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	5237000	usd
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	4012000	usd
CY2022	bhlb	Income Tax Expense Benefit Valuation Allowance Change In Amount IncomeTaxExpenseBenefitValuationAllowanceChangeInAmount	0	usd
CY2021	bhlb	Income Tax Expense Benefit Valuation Allowance Change In Amount IncomeTaxExpenseBenefitValuationAllowanceChangeInAmount	-200000	usd
CY2020	bhlb	Income Tax Expense Benefit Valuation Allowance Change In Amount IncomeTaxExpenseBenefitValuationAllowanceChangeInAmount	0	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21285000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30357000	usd
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-19853000	usd
CY2022	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	0	usd
CY2021	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	0	usd
CY2020	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	-7013000	usd
CY2022	us-gaap	Income Tax Expense Benefit Intraperiod Tax Allocation IncomeTaxExpenseBenefitIntraperiodTaxAllocation	21285000	usd
CY2021	us-gaap	Income Tax Expense Benefit Intraperiod Tax Allocation IncomeTaxExpenseBenefitIntraperiodTaxAllocation	30357000	usd
CY2020	us-gaap	Income Tax Expense Benefit Intraperiod Tax Allocation IncomeTaxExpenseBenefitIntraperiodTaxAllocation	-26866000	usd
CY2020Q4	bhlb	Current Income Tax Expense Benefit Net Operating Loss Cares Act CurrentIncomeTaxExpenseBenefitNetOperatingLossCARESAct	-6000000	usd
CY2021Q4	bhlb	Current Income Tax Expense Benefit Net Operating Loss Cares Act CurrentIncomeTaxExpenseBenefitNetOperatingLossCARESAct	-500000	usd
CY2022	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	23902000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2021	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	31294000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	-111936000	usd
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2022	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	4459000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.039
CY2021	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	6077000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.041
CY2020	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	-1589000	usd
CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.003
CY2022	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	3515000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.031
CY2021	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	3475000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.023
CY2020	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	3184000	usd
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	-0.006
CY2022	bhlb	Effective Income Tax Rate Reconciliation Bank Owned Life Insurance EffectiveIncomeTaxRateReconciliationBankOwnedLifeInsurance	1258000	usd
CY2022	bhlb	Effective Income Tax Rate Reconciliation Bank Owned Life Insurance Percent EffectiveIncomeTaxRateReconciliationBankOwnedLifeInsurancePercent	0.011
CY2021	bhlb	Effective Income Tax Rate Reconciliation Bank Owned Life Insurance EffectiveIncomeTaxRateReconciliationBankOwnedLifeInsurance	1348000	usd
CY2021	bhlb	Effective Income Tax Rate Reconciliation Bank Owned Life Insurance Percent EffectiveIncomeTaxRateReconciliationBankOwnedLifeInsurancePercent	0.009
CY2020	bhlb	Effective Income Tax Rate Reconciliation Bank Owned Life Insurance EffectiveIncomeTaxRateReconciliationBankOwnedLifeInsurance	1283000	usd
CY2020	bhlb	Effective Income Tax Rate Reconciliation Bank Owned Life Insurance Percent EffectiveIncomeTaxRateReconciliationBankOwnedLifeInsurancePercent	-0.003
CY2022	us-gaap	Income Tax Reconciliation Nondeductible Expense Impairment Losses IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses	0	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Impairment Losses EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses
CY2021	us-gaap	Income Tax Reconciliation Nondeductible Expense Impairment Losses IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses	0	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Impairment Losses EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses	0
CY2020	us-gaap	Income Tax Reconciliation Nondeductible Expense Impairment Losses IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses	103912000	usd
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Impairment Losses EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses	-0.195
CY2022	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	2129000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.019
CY2021	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	2881000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.019
CY2020	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	1812000	usd
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	-0.003
CY2022	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	0	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0
CY2021	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	200000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.001
CY2020	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	0	usd
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0
CY2022	bhlb	Effective Income Tax Rate Reconciliation Tax Rate Benefit On Net Operating Loss Carryback Amount EffectiveIncomeTaxRateReconciliationTaxRateBenefitOnNetOperatingLossCarrybackAmount	0	usd
CY2022	bhlb	Effective Income Tax Rate Reconciliation Tax Rate Benefit On Net Operating Loss Carryback Percent EffectiveIncomeTaxRateReconciliationTaxRateBenefitOnNetOperatingLossCarrybackPercent	0
CY2021	bhlb	Effective Income Tax Rate Reconciliation Tax Rate Benefit On Net Operating Loss Carryback Amount EffectiveIncomeTaxRateReconciliationTaxRateBenefitOnNetOperatingLossCarrybackAmount	-493000	usd
CY2021	bhlb	Effective Income Tax Rate Reconciliation Tax Rate Benefit On Net Operating Loss Carryback Percent EffectiveIncomeTaxRateReconciliationTaxRateBenefitOnNetOperatingLossCarrybackPercent	-0.003
CY2020	bhlb	Effective Income Tax Rate Reconciliation Tax Rate Benefit On Net Operating Loss Carryback Amount EffectiveIncomeTaxRateReconciliationTaxRateBenefitOnNetOperatingLossCarrybackAmount	-6040000	usd
CY2020	bhlb	Effective Income Tax Rate Reconciliation Tax Rate Benefit On Net Operating Loss Carryback Percent EffectiveIncomeTaxRateReconciliationTaxRateBenefitOnNetOperatingLossCarrybackPercent	0.011
CY2022	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	-174000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.001
CY2021	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	983000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.006
CY2020	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	2079000	usd
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.004
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21285000	usd
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.187
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30357000	usd
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.204
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-19853000	usd
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.037
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	28312000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	30441000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Investments DeferredTaxAssetsInvestments	1603000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Investments DeferredTaxAssetsInvestments	1451000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Other Comprehensive Loss DeferredTaxAssetsOtherComprehensiveLoss	63335000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Other Comprehensive Loss DeferredTaxAssetsOtherComprehensiveLoss	1085000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	11659000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	8435000	usd
CY2022Q4	bhlb	Deferred Tax Assets Purchase Accounting Adjustments DeferredTaxAssetsPurchaseAccountingAdjustments	4342000	usd
CY2021Q4	bhlb	Deferred Tax Assets Purchase Accounting Adjustments DeferredTaxAssetsPurchaseAccountingAdjustments	4829000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	503000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	1139000	usd
CY2022Q4	bhlb	Deferred Tax Assets Deferred Loan Fees DeferredTaxAssetsDeferredLoanFees	4049000	usd
CY2021Q4	bhlb	Deferred Tax Assets Deferred Loan Fees DeferredTaxAssetsDeferredLoanFees	2449000	usd
CY2022Q4	bhlb	Deferred Tax Assets Operating Lease Liability DeferredTaxAssetsOperatingLeaseLiability	14148000	usd
CY2021Q4	bhlb	Deferred Tax Assets Operating Lease Liability DeferredTaxAssetsOperatingLeaseLiability	14940000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	2630000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	1850000	usd
CY2022Q4	bhlb	Deferred Tax Asset Nonaccrual Interest DeferredTaxAssetNonaccrualInterest	1069000	usd
CY2021Q4	bhlb	Deferred Tax Asset Nonaccrual Interest DeferredTaxAssetNonaccrualInterest	1722000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Goodwill And Intangible Assets DeferredTaxAssetsGoodwillAndIntangibleAssets	659000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Goodwill And Intangible Assets DeferredTaxAssetsGoodwillAndIntangibleAssets	0	usd
CY2022Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	1778000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	1845000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	134087000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	70186000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	400000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	400000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	133687000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	69786000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	1212000	usd
CY2021Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	1488000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	0	usd
CY2021Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	545000	usd
CY2022Q4	bhlb	Deferred Tax Liabilities Unamortized Tax Credit Reserve DeferredTaxLiabilitiesUnamortizedTaxCreditReserve	1687000	usd
CY2021Q4	bhlb	Deferred Tax Liabilities Unamortized Tax Credit Reserve DeferredTaxLiabilitiesUnamortizedTaxCreditReserve	1075000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	12457000	usd
CY2021Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	14058000	usd
CY2022Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	15356000	usd
CY2021Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	17166000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	118331000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	52620000	usd
CY2022	bhlb	Deferred Tax Assets Liabilities Net Increase Decrease DeferredTaxAssetsLiabilitiesNetIncreaseDecrease	65700000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	62300000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	400000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	400000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Domestic DeferredTaxAssetsOperatingLossCarryforwardsDomestic	315000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	188000	usd
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1025000	usd
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	516000	usd
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	238000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	17000	usd
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	509000	usd
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	309000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2022	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	usd
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	usd
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	usd
CY2022	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	0	usd
CY2021	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	0	usd
CY2020	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	31000	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1042000	usd
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1025000	usd
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	516000	usd
CY2022Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	4500000000	usd
CY2022Q4	bhlb	Derivative Securities Pledged As Collateral Amortized Cost DerivativeSecuritiesPledgedAsCollateralAmortizedCost	12000000	usd
CY2022Q4	us-gaap	Financial Instruments Owned At Fair Value FinancialInstrumentsOwnedAtFairValue	12000000	usd
CY2021Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	43700000	usd
CY2021Q4	bhlb	Derivative Securities Pledged As Collateral Amortized Cost DerivativeSecuritiesPledgedAsCollateralAmortizedCost	34800000	usd
CY2021Q4	us-gaap	Financial Instruments Owned At Fair Value FinancialInstrumentsOwnedAtFairValue	34900000	usd
CY2022Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	4524514000	usd
CY2022Q4	us-gaap	Derivative Assets Liabilities At Fair Value Net DerivativeAssetsLiabilitiesAtFairValueNet	-43167000	usd
CY2022Q4	bhlb	Fair Value Estimates Impactof Settledto Market Contract FairValueEstimatesImpactofSettledtoMarketContract	38300000	usd
CY2021Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	3711905000	usd
CY2021Q4	us-gaap	Derivative Assets Liabilities At Fair Value Net DerivativeAssetsLiabilitiesAtFairValueNet	43426000	usd
CY2021Q4	bhlb	Fair Value Estimates Impactof Settledto Market Contract FairValueEstimatesImpactofSettledtoMarketContract	45700000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	46411000	usd
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	52180000	usd
CY2022Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	6151000	usd
CY2021Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	6674000	usd
CY2022Q4	bhlb	Lease Rightof Use Asset LeaseRightofUseAsset	52562000	usd
CY2021Q4	bhlb	Lease Rightof Use Asset LeaseRightofUseAsset	58854000	usd
CY2022Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	53736000	usd
CY2021Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	55674000	usd
CY2022Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	9306000	usd
CY2021Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	9862000	usd
CY2022Q4	bhlb	Lease Liability LeaseLiability	63042000	usd
CY2021Q4	bhlb	Lease Liability LeaseLiability	65536000	usd
CY2022Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P9Y3M18D
CY2021Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P9Y6M
CY2022Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P11Y9M18D
CY2021Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P12Y9M18D
CY2022Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0256
CY2021Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0277
CY2022Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.0500
CY2021Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.0500
CY2022	us-gaap	Operating Lease Cost OperatingLeaseCost	9700000	usd
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	10900000	usd
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	13500000	usd
CY2022	us-gaap	Operating Lease Payments OperatingLeasePayments	9438000	usd
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	10897000	usd
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	13750000	usd
CY2022	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	476000	usd
CY2021	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	503000	usd
CY2020	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	530000	usd
CY2022	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	555000	usd
CY2021	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	528000	usd
CY2020	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	500000	usd
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	5730000	usd
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	2976000	usd
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	7083000	usd
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	0	usd
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	0	usd
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	0	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	9743000	usd
CY2022Q4	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	1035000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	8225000	usd
CY2022Q4	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	1037000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	6501000	usd
CY2022Q4	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	1037000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	5480000	usd
CY2022Q4	us-gaap	Finance Lease Liability Payments Due Year Four FinanceLeaseLiabilityPaymentsDueYearFour	1037000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	4713000	usd
CY2022Q4	us-gaap	Finance Lease Liability Payments Due Year Five FinanceLeaseLiabilityPaymentsDueYearFive	1037000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	25313000	usd
CY2022Q4	us-gaap	Finance Lease Liability Payments Due After Year Five FinanceLeaseLiabilityPaymentsDueAfterYearFive	7149000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	59975000	usd
CY2022Q4	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	12332000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	6239000	usd
CY2022Q4	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	3026000	usd
CY2022Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	53736000	usd
CY2022Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	9306000	usd
CY2022Q4	bhlb	Financing Receivable Modifications Active Modified Loans FinancingReceivableModificationsActiveModifiedLoans	1	loan
CY2022Q4	bhlb	Financing Receivable Modifications Active Modified Loans Carrying Value FinancingReceivableModificationsActiveModifiedLoansCarryingValue	12400000	usd
CY2021Q4	bhlb	Financing Receivable Modifications Active Modified Loans FinancingReceivableModificationsActiveModifiedLoans	19	loan
CY2021Q4	bhlb	Financing Receivable Modifications Active Modified Loans Carrying Value FinancingReceivableModificationsActiveModifiedLoansCarryingValue	14400000	usd
CY2022Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Amount Liability FairValueDisclosureOffbalanceSheetRisksAmountLiability	2324399000	usd
CY2021Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Amount Liability FairValueDisclosureOffbalanceSheetRisksAmountLiability	2180227000	usd
CY2022Q4	us-gaap	Capital Capital	1336029000	usd
CY2022Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1460
CY2022Q4	us-gaap	Capital Required For Capital Adequacy CapitalRequiredForCapitalAdequacy	732070000	usd
CY2022Q4	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0800
CY2022Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	1130522000	usd
CY2022Q4	us-gaap	Common Equity Tier One Capital Ratio CommonEquityTierOneCapitalRatio	0.1235
CY2022Q4	us-gaap	Common Equity Tier One Capital Required For Capital Adequacy CommonEquityTierOneCapitalRequiredForCapitalAdequacy	411789000	usd
CY2022Q4	us-gaap	Banking Regulation Common Equity Tier One Risk Based Capital Ratio Capital Adequacy Minimum BankingRegulationCommonEquityTierOneRiskBasedCapitalRatioCapitalAdequacyMinimum	0.0450
CY2022Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	1152808000	usd
CY2022Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.1260
CY2022Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy TierOneRiskBasedCapitalRequiredForCapitalAdequacy	549052000	usd
CY2022Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0600
CY2022Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	1152808000	usd
CY2022Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.1018
CY2022Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	366035000	usd
CY2022Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2022Q4	us-gaap	Risk Weighted Assets RiskWeightedAssets	9150869000	usd
CY2021Q4	us-gaap	Capital Capital	1359470000	usd
CY2021Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1732
CY2021Q4	us-gaap	Capital Required For Capital Adequacy CapitalRequiredForCapitalAdequacy	628026000	usd
CY2021Q4	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0800
CY2021Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	1178497000	usd
CY2021Q4	us-gaap	Common Equity Tier One Capital Ratio CommonEquityTierOneCapitalRatio	0.1501
CY2021Q4	us-gaap	Common Equity Tier One Capital Required For Capital Adequacy CommonEquityTierOneCapitalRequiredForCapitalAdequacy	353265000	usd
CY2021Q4	us-gaap	Banking Regulation Common Equity Tier One Risk Based Capital Ratio Well Capitalized Minimum BankingRegulationCommonEquityTierOneRiskBasedCapitalRatioWellCapitalizedMinimum	0.0450
CY2021Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	1200732000	usd
CY2021Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.1530
CY2021Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy TierOneRiskBasedCapitalRequiredForCapitalAdequacy	471020000	usd
CY2021Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0600
CY2021Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	1200732000	usd
CY2021Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.1049
CY2021Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	314013000	usd
CY2021Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2021Q4	us-gaap	Risk Weighted Assets RiskWeightedAssets	7850331000	usd
CY2022Q4	us-gaap	Banking Regulation Common Equity Tier One Risk Based Capital Ratio Capital Adequacy Minimum BankingRegulationCommonEquityTierOneRiskBasedCapitalRatioCapitalAdequacyMinimum	0.0450
CY2021Q4	us-gaap	Banking Regulation Common Equity Tier One Risk Based Capital Ratio Capital Adequacy Minimum BankingRegulationCommonEquityTierOneRiskBasedCapitalRatioCapitalAdequacyMinimum	0.0450
CY2022	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-240074000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-62265000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-177809000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-45801000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-11687000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-34114000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	25237000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	6359000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	18878000	usd
CY2022	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-177805000	usd
CY2022	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	4000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-177809000	usd
CY2021	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-34114000	usd
CY2021	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	0	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-34114000	usd
CY2020	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	18874000	usd
CY2020	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-4000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	18878000	usd
CY2022	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	92533000	usd
CY2021	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	118664000	usd
CY2020	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-513175000	usd
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	0	usd
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	0	usd
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-19842000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	92533000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	118664000	usd
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-533017000	usd
CY2022	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	51903000	shares
CY2021	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	51903000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	51903000	shares
CY2022	us-gaap	Weighted Average Number Of Shares Treasury Stock WeightedAverageNumberOfSharesTreasuryStock	5577000	shares
CY2021	us-gaap	Weighted Average Number Of Shares Treasury Stock WeightedAverageNumberOfSharesTreasuryStock	1951000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Treasury Stock WeightedAverageNumberOfSharesTreasuryStock	1569000	shares
CY2022	us-gaap	Weighted Average Number Of Shares Restricted Stock WeightedAverageNumberOfSharesRestrictedStock	762000	shares
CY2021	us-gaap	Weighted Average Number Of Shares Restricted Stock WeightedAverageNumberOfSharesRestrictedStock	712000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Restricted Stock WeightedAverageNumberOfSharesRestrictedStock	505000	shares
CY2022	bhlb	Weighted Average Numberof Shares Outstanding Preferred Stock WeightedAverageNumberofSharesOutstandingPreferredStock	0	shares
CY2021	bhlb	Weighted Average Numberof Shares Outstanding Preferred Stock WeightedAverageNumberofSharesOutstandingPreferredStock	0	shares
CY2020	bhlb	Weighted Average Numberof Shares Outstanding Preferred Stock WeightedAverageNumberofSharesOutstandingPreferredStock	441000	shares
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	45564000	shares
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	49240000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	50270000	shares
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	45914000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	49554000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	50270000	shares
CY2022	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	2.03
CY2021	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	2.41
CY2020	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-10.21
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-0.39
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.03
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.41
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-10.60
CY2022	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	2.02
CY2021	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	2.39
CY2020	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-10.21
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	-0.39
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.02
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.39
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-10.60
CY2022	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	0	usd
CY2021	bhlb	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 Number Of Transfers FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3NumberOfTransfers	1	transfer
CY2021	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	4000000	usd
CY2022	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	0	usd
CY2022	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	98032000	usd
CY2021	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	0	usd
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	0	usd
CY2022Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	121384000	usd
CY2022Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	103671000	usd
CY2022Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	87379000	usd
CY2022Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	74823000	usd
CY2021Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	75860000	usd
CY2021Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	79688000	usd
CY2021Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	85364000	usd
CY2021Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	88153000	usd
CY2022Q4	us-gaap	Interest Expense InterestExpense	19292000	usd
CY2022Q3	us-gaap	Interest Expense InterestExpense	11587000	usd
CY2022Q2	us-gaap	Interest Expense InterestExpense	6021000	usd
CY2022Q1	us-gaap	Interest Expense InterestExpense	5760000	usd
CY2021Q4	us-gaap	Interest Expense InterestExpense	6548000	usd
CY2021Q3	us-gaap	Interest Expense InterestExpense	8320000	usd
CY2021Q2	us-gaap	Interest Expense InterestExpense	9971000	usd
CY2021Q1	us-gaap	Interest Expense InterestExpense	13060000	usd
CY2022Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	102092000	usd
CY2022Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	92084000	usd
CY2022Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	81358000	usd
CY2022Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	69063000	usd
CY2021Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	69312000	usd
CY2021Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	71368000	usd
CY2021Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	75393000	usd
CY2021Q1	us-gaap	Revenues Revenues	101286000	usd
CY2021Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	75093000	usd
CY2022Q4	us-gaap	Noninterest Income NoninterestIncome	15654000	usd
CY2022Q3	us-gaap	Noninterest Income NoninterestIncome	16251000	usd
CY2022Q2	us-gaap	Noninterest Income NoninterestIncome	16351000	usd
CY2022Q1	us-gaap	Noninterest Income NoninterestIncome	20681000	usd
CY2021Q4	us-gaap	Noninterest Income NoninterestIncome	21409000	usd
CY2021Q3	us-gaap	Noninterest Income NoninterestIncome	73635000	usd
CY2021Q2	us-gaap	Noninterest Income NoninterestIncome	22011000	usd
CY2021Q1	us-gaap	Noninterest Income NoninterestIncome	26193000	usd
CY2022Q4	us-gaap	Revenues Revenues	117746000	usd
CY2022Q3	us-gaap	Revenues Revenues	108335000	usd
CY2022Q2	us-gaap	Revenues Revenues	97709000	usd
CY2022Q1	us-gaap	Revenues Revenues	89744000	usd
CY2021Q4	us-gaap	Revenues Revenues	90721000	usd
CY2021Q3	us-gaap	Revenues Revenues	145003000	usd
CY2021Q2	us-gaap	Revenues Revenues	97404000	usd
CY2022Q4	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	12000000	usd
CY2022Q3	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	3000000	usd
CY2022Q2	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	0	usd
CY2022Q1	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-4000000	usd
CY2021Q4	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-3000000	usd
CY2021Q3	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-4000000	usd
CY2021Q2	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	0	usd
CY2021Q1	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	6500000	usd
CY2022Q4	us-gaap	Noninterest Expense NoninterestExpense	70014000	usd
CY2022Q3	us-gaap	Noninterest Expense NoninterestExpense	81677000	usd
CY2022Q2	us-gaap	Noninterest Expense NoninterestExpense	68475000	usd
CY2022Q1	us-gaap	Noninterest Expense NoninterestExpense	68550000	usd
CY2021Q4	us-gaap	Noninterest Expense NoninterestExpense	69407000	usd
CY2021Q3	us-gaap	Noninterest Expense NoninterestExpense	69460000	usd
CY2021Q2	us-gaap	Noninterest Expense NoninterestExpense	68872000	usd
CY2021Q1	us-gaap	Noninterest Expense NoninterestExpense	78154000	usd
CY2022Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	35732000	usd
CY2022Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	23658000	usd
CY2022Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	29234000	usd
CY2022Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	25194000	usd
CY2021Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	24314000	usd
CY2021Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	79543000	usd
CY2021Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	28532000	usd
CY2021Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	16632000	usd
CY2022Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	5227000	usd
CY2022Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	4941000	usd
CY2022Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	6119000	usd
CY2022Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	4998000	usd
CY2021Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	4066000	usd
CY2021Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	15794000	usd
CY2021Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	6896000	usd
CY2021Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3601000	usd
CY2022Q4	us-gaap	Net Income Loss NetIncomeLoss	30505000	usd
CY2022Q3	us-gaap	Net Income Loss NetIncomeLoss	18717000	usd
CY2022Q2	us-gaap	Net Income Loss NetIncomeLoss	23115000	usd
CY2022Q1	us-gaap	Net Income Loss NetIncomeLoss	20196000	usd
CY2021Q4	us-gaap	Net Income Loss NetIncomeLoss	20248000	usd
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	63749000	usd
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	21636000	usd
CY2021Q1	us-gaap	Net Income Loss NetIncomeLoss	13031000	usd
CY2022Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.69
CY2022Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.42
CY2022Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.50
CY2022Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.42
CY2021Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.42
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.32
CY2021Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.43
CY2021Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.26
CY2022Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.69
CY2022Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.42
CY2022Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.50
CY2022Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.42
CY2021Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.42
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.31
CY2021Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.43
CY2021Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.26
CY2022Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	44105000	shares
CY2022Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	44700000	shares
CY2022Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	45818000	shares
CY2022Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	47668000	shares
CY2021Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	47958000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	48395000	shares
CY2021Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	50321000	shares
CY2021Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	50330000	shares
CY2022Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	44484000	shares
CY2022Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	45034000	shares
CY2022Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	46102000	shares
CY2022Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	48067000	shares
CY2021Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	48340000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	48744000	shares
CY2021Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	50608000	shares
CY2021Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	50565000	shares
CY2022	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	344597000	usd
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	291166000	usd
CY2020	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	316782000	usd
CY2022	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	11000000	usd
CY2021	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-500000	usd
CY2020	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	75878000	usd
CY2022	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	333597000	usd
CY2021	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	291666000	usd
CY2020	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	240904000	usd
CY2022	us-gaap	Noninterest Income NoninterestIncome	68937000	usd
CY2021	us-gaap	Noninterest Income NoninterestIncome	143248000	usd
CY2020	us-gaap	Noninterest Income NoninterestIncome	66307000	usd
CY2022	us-gaap	Noninterest Expense NoninterestExpense	288716000	usd
CY2021	us-gaap	Noninterest Expense NoninterestExpense	285893000	usd
CY2020	us-gaap	Noninterest Expense NoninterestExpense	840239000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	113818000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	149021000	usd
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-533028000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21285000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30357000	usd
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-19853000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	92533000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	118664000	usd
CY2020	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	-513175000	usd
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	46853000	usd
CY2022	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax	0	usd
CY2021	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax	0	usd
CY2020	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax	-26855000	usd
CY2022	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	0	usd
CY2021	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	0	usd
CY2020	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	-7013000	usd
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	usd
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	usd
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	-19842000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	92533000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	118664000	usd
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-533017000	usd
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	40874000	usd
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	46103000	usd
CY2022	us-gaap	Revenue Not From Contract With Customer RevenueNotFromContractWithCustomer	28063000	usd
CY2021	us-gaap	Revenue Not From Contract With Customer RevenueNotFromContractWithCustomer	97145000	usd
CY2020	us-gaap	Revenue Not From Contract With Customer RevenueNotFromContractWithCustomer	19454000	usd
CY2022	us-gaap	Noninterest Income NoninterestIncome	68937000	usd
CY2021	us-gaap	Noninterest Income NoninterestIncome	143248000	usd
CY2020	us-gaap	Noninterest Income NoninterestIncome	66307000	usd

Files In Submission

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$BHLB
BERKSHIRE HILLS BANCORP INC Stock $bhlb

2023 Q1 Form 10-K Financial Statement

#000110813423000006 Filed on March 01, 2023

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$BHLB BERKSHIRE HILLS BANCORP INC Stock $bhlb

2023 Q1 Form 10-K Financial Statement

#000110813423000006 Filed on March 01, 2023

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$BHLB
BERKSHIRE HILLS BANCORP INC Stock $bhlb