$EBC
Eastern Bankshares, Inc. Stock $ebc

$ebc Overview Financials Valuation SEC Filings Company Website

2024 Q1 Form 10-K Financial Statement

#000162828024006922 Filed on February 26, 2024

Income Statement

Concept	2024 Q1	2023 Q4	2023
Revenue	$20.43M		$76.87M
YoY Change	-58.49%		-56.47%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$3.332M	$3.254M	$12.30M
YoY Change	-10.41%	-17.33%	-17.8%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$72.71M		$246.1M
YoY Change	43.78%		562.73%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$48.94M	$33.82M	-$126.0M
YoY Change	-119.09%	-33.52%	-149.09%
Income Tax	$10.29M	$2.310M	-$63.31M
% Of Pretax Income	21.03%	6.83%
Net Earnings	$38.65M	$318.5M	$232.2M
YoY Change	-119.91%	653.07%	16.23%
Net Earnings / Revenue	189.21%		302.05%
Basic Earnings Per Share	$0.24		$1.43
Diluted Earnings Per Share	$0.24	$1.95	$1.43
COMMON SHARES
Basic Shares Outstanding	176.4M shares	176.4M shares	162.3M shares
Diluted Shares Outstanding	163.2M shares		162.4M shares

Balance Sheet

Concept	2024 Q1	2023 Q4	2023
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$739.0M	$693.1M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$59.79M	$60.13M	$60.13M
YoY Change	-2.16%	-4.03%	-4.03%
Goodwill		$557.6M
YoY Change		-12.9%
Intangibles
YoY Change
Long-Term Investments
YoY Change
Other Assets	$272.3M	$266.2M	$266.2M
YoY Change	-13.3%	-19.74%	-19.74%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$21.17B	$21.13B	$21.13B
YoY Change	-6.8%	-6.68%	-6.68%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$54.96M	$55.62M	$55.62M
YoY Change	-7.57%	-9.14%	-9.14%
Deferred Revenue
YoY Change
Short-Term Debt
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$54.96M	$55.62M	$55.62M
YoY Change	-7.57%	-9.14%	-9.14%
LONG-TERM LIABILITIES
Long-Term Debt	$0.00	$0.00	$0.00
YoY Change
Other Long-Term Liabilities	$513.3M	$522.5M	$522.5M
YoY Change	24.06%	10.16%	10.16%
Total Long-Term Liabilities	$513.3M	$522.5M	$522.5M
YoY Change	24.06%	10.16%	10.16%
TOTAL LIABILITIES
Total Short-Term Liabilities	$54.96M	$55.62M	$55.62M
Total Long-Term Liabilities	$513.3M	$522.5M	$522.5M
Total Liabilities	$18.22B	$18.16B	$18.16B
YoY Change	-9.53%	-10.0%	-10.0%
SHAREHOLDERS EQUITY
Retained Earnings	$2.068B	$2.048B
YoY Change	23.69%	8.82%
Common Stock	$1.769M	$1.767M
YoY Change	0.28%	0.28%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$2.953B	$2.975B	$2.975B
YoY Change
Total Liabilities & Shareholders Equity	$21.17B	$21.13B	$21.13B
YoY Change	-6.8%	-6.68%	-6.68%

Cashflow Statement

Concept	2024 Q1	2023 Q4	2023
OPERATING ACTIVITIES
Net Income	$38.65M	$318.5M	$232.2M
YoY Change	-119.91%	653.07%	16.23%
Depreciation, Depletion And Amortization	$3.332M	$3.254M	$12.30M
YoY Change	-10.41%	-17.33%	-17.8%
Cash From Operating Activities	$32.57M	$52.76M	$261.7M
YoY Change	-67.6%	1434.61%	13.81%
INVESTING ACTIVITIES
Capital Expenditures	$2.485M	$3.850M	$8.140M
YoY Change	104.19%	71.42%	-5.65%
Acquisitions			$0.00
YoY Change			-100.0%
Other Investing Activities	-$41.30M	$548.4M	$2.408B
YoY Change	-102.15%	-209.26%	-325.5%
Cash From Investing Activities	-$43.79M	$544.6M	$2.400B
YoY Change	-102.28%	-208.01%	-322.94%
FINANCING ACTIVITIES
Cash Dividend Paid	$17.89M	$18.00M	$66.67M
YoY Change	10.43%	11.8%	1.19%
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	$57.17M	-513.1M	-$2.138B
YoY Change	-210.43%	-200.25%	891.95%
NET CHANGE
Cash From Operating Activities	$32.57M	52.76M	$261.7M
Cash From Investing Activities	-$43.79M	544.6M	$2.400B
Cash From Financing Activities	$57.17M	-513.1M	-$2.138B
Net Change In Cash	$45.94M	84.27M	$523.6M
YoY Change	-97.67%	661.37%	-149.29%
FREE CASH FLOW
Cash From Operating Activities	$32.57M	$52.76M	$261.7M
Capital Expenditures	$2.485M	$3.850M	$8.140M
Free Cash Flow	$30.08M	$48.91M	$253.6M
YoY Change	-69.71%	4003.19%	14.57%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2021	ebc	Taxable Interest And Dividends On Available For Sale Securities TaxableInterestAndDividendsOnAvailableForSaleSecurities	58312000	usd
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CY2021	ebc	Nontaxable Interest And Dividends On Available For Sale Securities NontaxableInterestAndDividendsOnAvailableForSaleSecurities	7376000	usd
CY2022	ebc	Interest On Federal Funds Sold And Other Short Term Investments InterestOnFederalFundsSoldAndOtherShortTermInvestments	3271000	usd
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CY2023	dei	Document Period End Date DocumentPeriodEndDate	2023-12-31
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CY2023	dei	Entity File Number EntityFileNumber	001-39610
CY2023	dei	Entity Registrant Name EntityRegistrantName	Eastern Bankshares, Inc.
CY2023	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	MA
CY2023	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	84-4199750
CY2023	dei	Entity Address Address Line1 EntityAddressAddressLine1	265 Franklin Street
CY2023	dei	Entity Address City Or Town EntityAddressCityOrTown	Boston
CY2023	dei	Entity Address State Or Province EntityAddressStateOrProvince	MA
CY2023	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	02110
CY2023	dei	City Area Code CityAreaCode	800
CY2023	dei	Local Phone Number LocalPhoneNumber	327-8376
CY2023	dei	Security12b Title Security12bTitle	Common Stock
CY2023	dei	Trading Symbol TradingSymbol	EBC
CY2023	dei	Security Exchange Name SecurityExchangeName	NASDAQ
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CY2023	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
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CY2023Q4	us-gaap	Deposits Deposits	17596217000	usd
CY2022Q4	us-gaap	Deposits Deposits	18974359000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	95000	usd
CY2022Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	691297000	usd
CY2023Q4	ebc	Escrow Deposits Of Borrowers EscrowDepositsOfBorrowers	21978000	usd
CY2022Q4	ebc	Escrow Deposits Of Borrowers EscrowDepositsOfBorrowers	22314000	usd
CY2023Q4	ebc	Interest Rate Swap Collateral Funds InterestRateSwapCollateralFunds	8500000	usd
CY2022Q4	ebc	Interest Rate Swap Collateral Funds InterestRateSwapCollateralFunds	14430000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	17643000	usd
CY2022Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	12787000	usd
CY2023Q4	us-gaap	Debt Longterm And Shortterm Combined Amount DebtLongtermAndShorttermCombinedAmount	48216000	usd
CY2022Q4	us-gaap	Debt Longterm And Shortterm Combined Amount DebtLongtermAndShorttermCombinedAmount	740828000	usd
CY2023Q4	us-gaap	Other Liabilities OtherLiabilities	513990000	usd
CY2022Q4	us-gaap	Other Liabilities OtherLiabilities	424951000	usd
CY2023Q4	us-gaap	Liabilities Of Disposal Group Including Discontinued Operation LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation	0	usd
CY2022Q4	us-gaap	Liabilities Of Disposal Group Including Discontinued Operation LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation	34930000	usd
CY2023Q4	us-gaap	Liabilities Liabilities	18158423000	usd
CY2022Q4	us-gaap	Liabilities Liabilities	20175068000	usd
CY2023Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies	0	usd
CY2022Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies	0	usd
CY2023Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2022Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2023Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2022Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2023Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	176426993	shares
CY2022Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	176172073	shares
CY2022Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	176172073	shares
CY2023Q4	us-gaap	Common Stock Value CommonStockValue	1767000	usd
CY2022Q4	us-gaap	Common Stock Value CommonStockValue	1762000	usd
CY2023Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	1666441000	usd
CY2022Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	1649141000	usd
CY2023Q4	us-gaap	Unearned Esop Shares UnearnedESOPShares	132755000	usd
CY2022Q4	us-gaap	Unearned Esop Shares UnearnedESOPShares	137696000	usd
CY2023Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	2047754000	usd
CY2022Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1881775000	usd
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-608352000	usd
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-923192000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	2974855000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	2471790000	usd
CY2023Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	21133278000	usd
CY2022Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	22646858000	usd
CY2023	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	652095000	usd
CY2021	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	367585000	usd
CY2023	ebc	Nontaxable Interest And Dividends On Available For Sale Securities NontaxableInterestAndDividendsOnAvailableForSaleSecurities	5736000	usd
CY2023	ebc	Interest On Federal Funds Sold And Other Short Term Investments InterestOnFederalFundsSoldAndOtherShortTermInvestments	37395000	usd
CY2023	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	796459000	usd
CY2022	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	605181000	usd
CY2023	us-gaap	Interest Expense Deposits InterestExpenseDeposits	226075000	usd
CY2022	us-gaap	Interest Expense Deposits InterestExpenseDeposits	28621000	usd
CY2021	us-gaap	Interest Expense Deposits InterestExpenseDeposits	5167000	usd
CY2023	us-gaap	Interest Expense Borrowings InterestExpenseBorrowings	19975000	usd
CY2022	us-gaap	Interest Expense Borrowings InterestExpenseBorrowings	8506000	usd
CY2021	us-gaap	Interest Expense Borrowings InterestExpenseBorrowings	165000	usd
CY2023	us-gaap	Interest Expense InterestExpense	246050000	usd
CY2022	us-gaap	Interest Expense InterestExpense	37127000	usd
CY2021	us-gaap	Interest Expense InterestExpense	5332000	usd
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	429827000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	17925000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	-9686000	usd
CY2023	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	530357000	usd
CY2022	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	550129000	usd
CY2021	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	439513000	usd
CY2023	ebc	Service Charges On Deposit Accounts ServiceChargesOnDepositAccounts	28631000	usd
CY2022	ebc	Service Charges On Deposit Accounts ServiceChargesOnDepositAccounts	30392000	usd
CY2021	ebc	Service Charges On Deposit Accounts ServiceChargesOnDepositAccounts	24271000	usd
CY2023	ebc	Trust And Investment Advisory Fees TrustAndInvestmentAdvisoryFees	24264000	usd
CY2022	ebc	Trust And Investment Advisory Fees TrustAndInvestmentAdvisoryFees	23593000	usd
CY2021	ebc	Trust And Investment Advisory Fees TrustAndInvestmentAdvisoryFees	24588000	usd
CY2023	ebc	Debit Card Processing Fees DebitCardProcessingFees	13469000	usd
CY2022	ebc	Debit Card Processing Fees DebitCardProcessingFees	12644000	usd
CY2021	ebc	Debit Card Processing Fees DebitCardProcessingFees	12118000	usd
CY2023	ebc	Interest Rate Swap Income Losses InterestRateSwapIncomeLosses	1536000	usd
CY2022	ebc	Interest Rate Swap Income Losses InterestRateSwapIncomeLosses	6009000	usd
CY2021	ebc	Interest Rate Swap Income Losses InterestRateSwapIncomeLosses	5634000	usd
CY2023	ebc	Income Losses From Investments Held In Rabbi Trusts IncomeLossesFromInvestmentsHeldInRabbiTrusts	9305000	usd
CY2022	ebc	Income Losses From Investments Held In Rabbi Trusts IncomeLossesFromInvestmentsHeldInRabbiTrusts	-10762000	usd
CY2021	ebc	Income Losses From Investments Held In Rabbi Trusts IncomeLossesFromInvestmentsHeldInRabbiTrusts	10217000	usd
CY2023	ebc	Gain Loss On Sale Of Commercial And Industrial Loans GainLossOnSaleOfCommercialAndIndustrialLoans	-2738000	usd
CY2022	ebc	Gain Loss On Sale Of Commercial And Industrial Loans GainLossOnSaleOfCommercialAndIndustrialLoans	0	usd
CY2021	ebc	Gain Loss On Sale Of Commercial And Industrial Loans GainLossOnSaleOfCommercialAndIndustrialLoans	0	usd
CY2023	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	-507000	usd
CY2022	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	248000	usd
CY2021	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	3605000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-333170000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-3157000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	1166000	usd
CY2023	us-gaap	Noninterest Income Other NoninterestIncomeOther	21457000	usd
CY2022	us-gaap	Noninterest Income Other NoninterestIncomeOther	17783000	usd
CY2021	us-gaap	Noninterest Income Other NoninterestIncomeOther	15838000	usd
CY2023	us-gaap	Noninterest Income NoninterestIncome	-237753000	usd
CY2022	us-gaap	Noninterest Income NoninterestIncome	76750000	usd
CY2021	us-gaap	Noninterest Income NoninterestIncome	97437000	usd
CY2023	us-gaap	Labor And Related Expense LaborAndRelatedExpense	253037000	usd
CY2022	us-gaap	Labor And Related Expense LaborAndRelatedExpense	233097000	usd
CY2021	us-gaap	Labor And Related Expense LaborAndRelatedExpense	227624000	usd
CY2023	us-gaap	Occupancy Net OccupancyNet	35992000	usd
CY2022	us-gaap	Occupancy Net OccupancyNet	37445000	usd
CY2021	us-gaap	Occupancy Net OccupancyNet	37261000	usd
CY2022	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	52938000	usd
CY2021	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	46415000	usd
CY2021	us-gaap	Professional Fees ProfessionalFees	21283000	usd
CY2023	us-gaap	Loan Processing Fee LoanProcessingFee	4466000	usd
CY2022	us-gaap	Loan Processing Fee LoanProcessingFee	6384000	usd
CY2021	us-gaap	Loan Processing Fee LoanProcessingFee	9114000	usd
CY2022	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	6250000	usd
CY2021	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	4226000	usd
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	219000	usd
CY2022	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	201618000	usd
CY2022	us-gaap	Stock Issued During Period Value Restricted Stock Award Gross StockIssuedDuringPeriodValueRestrictedStockAwardGross	0	usd
CY2022	us-gaap	Stock Issued During Period Value Restricted Stock Award Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures	0	usd
CY2022	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	10507000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	232177000	usd
CY2023	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.39
CY2022	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.13
CY2023	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	1.82
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.08
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.05
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.43
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.21
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.90
CY2023	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.39
CY2022	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.13
CY2021	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.85
CY2023	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	1.82
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.08
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.05
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.43
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.21
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.90
CY2023	us-gaap	Net Income Loss NetIncomeLoss	232177000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	199759000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	154665000	usd
CY2023	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	295913000	usd
CY2022	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-821570000	usd
CY2021	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-104258000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	18588000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	-57520000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	-22454000	usd
CY2023	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	-339000	usd
CY2022	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	-12594000	usd
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	-15782000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	314840000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-866496000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-110930000	usd
CY2023	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	547017000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-666737000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	43735000	usd
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	3428052000	usd
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	51619000	usd
CY2021	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	23224000	usd
CY2021	us-gaap	Stock Issued During Period Value Restricted Stock Award Gross StockIssuedDuringPeriodValueRestrictedStockAwardGross	0	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	154665000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-110930000	usd
CY2021	ebc	Employee Stock Ownership Plan Esop Value Committed To Be Released Shares EmployeeStockOwnershipPlanESOPValueCommittedToBeReleasedShares	9408000	usd
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	3406352000	usd
CY2022	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	66539000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	199759000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-866496000	usd
CY2022	ebc	Employee Stock Ownership Plan Esop Value Committed To Be Released Shares EmployeeStockOwnershipPlanESOPValueCommittedToBeReleasedShares	9923000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	2471790000	usd
CY2023	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	67020000	usd
CY2023	us-gaap	Stock Issued During Period Value Restricted Stock Award Gross StockIssuedDuringPeriodValueRestrictedStockAwardGross	0	usd
CY2023	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-1396000	usd
CY2023	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	16513000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	232177000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	314840000	usd
CY2023	ebc	Employee Stock Ownership Plan Esop Value Committed To Be Released Shares EmployeeStockOwnershipPlanESOPValueCommittedToBeReleasedShares	7129000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	2974855000	usd
CY2023	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-62689000	usd
CY2022	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	186511000	usd
CY2021	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	145531000	usd
CY2023	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	294866000	usd
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	13248000	usd
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	9134000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	232177000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	199759000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	154665000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	20052000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	17925000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	-9686000	usd
CY2023	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	12295000	usd
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	11985000	usd
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	11900000	usd
CY2023	ebc	Change In Unamortized Net Loan Costs And Premiums ChangeInUnamortizedNetLoanCostsAndPremiums	6445000	usd
CY2022	ebc	Change In Unamortized Net Loan Costs And Premiums ChangeInUnamortizedNetLoanCostsAndPremiums	-1441000	usd
CY2021	ebc	Change In Unamortized Net Loan Costs And Premiums ChangeInUnamortizedNetLoanCostsAndPremiums	-27991000	usd
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-18267000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	5262000	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-5663000	usd
CY2023	us-gaap	Amortization Of Debt Discount Premium AmortizationOfDebtDiscountPremium	6281000	usd
CY2022	us-gaap	Amortization Of Debt Discount Premium AmortizationOfDebtDiscountPremium	18274000	usd
CY2021	us-gaap	Amortization Of Debt Discount Premium AmortizationOfDebtDiscountPremium	16713000	usd
CY2023	us-gaap	Operating Lease Right Of Use Asset Amortization Expense OperatingLeaseRightOfUseAssetAmortizationExpense	11348000	usd
CY2022	us-gaap	Operating Lease Right Of Use Asset Amortization Expense OperatingLeaseRightOfUseAssetAmortizationExpense	11432000	usd
CY2021	us-gaap	Operating Lease Right Of Use Asset Amortization Expense OperatingLeaseRightOfUseAssetAmortizationExpense	10982000	usd
CY2023	us-gaap	Share Based Compensation ShareBasedCompensation	16047000	usd
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	10507000	usd
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	0	usd
CY2023	us-gaap	Increase Decrease In Insurance Settlements Receivable IncreaseDecreaseInInsuranceSettlementsReceivable	3912000	usd
CY2022	us-gaap	Increase Decrease In Insurance Settlements Receivable IncreaseDecreaseInInsuranceSettlementsReceivable	3699000	usd
CY2021	us-gaap	Increase Decrease In Insurance Settlements Receivable IncreaseDecreaseInInsuranceSettlementsReceivable	2348000	usd
CY2023	ebc	Bank Owned Life Insurance Income Expense BankOwnedLifeInsuranceIncomeExpense	0	usd
CY2022	ebc	Bank Owned Life Insurance Income Expense BankOwnedLifeInsuranceIncomeExpense	-663000	usd
CY2021	ebc	Bank Owned Life Insurance Income Expense BankOwnedLifeInsuranceIncomeExpense	1813000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-333170000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-3157000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	1166000	usd
CY2023	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	0	usd
CY2022	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	1412000	usd
CY2021	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-4715000	usd
CY2023	us-gaap	Gain Loss On Termination Of Lease GainLossOnTerminationOfLease	-395000	usd
CY2022	us-gaap	Gain Loss On Termination Of Lease GainLossOnTerminationOfLease	-593000	usd
CY2021	us-gaap	Gain Loss On Termination Of Lease GainLossOnTerminationOfLease	-2582000	usd
CY2023	us-gaap	Amortization Of Deferred Hedge Gains AmortizationOfDeferredHedgeGains	-46000	usd
CY2022	us-gaap	Amortization Of Deferred Hedge Gains AmortizationOfDeferredHedgeGains	-10193000	usd
CY2021	us-gaap	Amortization Of Deferred Hedge Gains AmortizationOfDeferredHedgeGains	-31234000	usd
CY2023	us-gaap	Employee Stock Ownership Plan Esop Compensation Expense EmployeeStockOwnershipPlanESOPCompensationExpense	7129000	usd
CY2022	us-gaap	Employee Stock Ownership Plan Esop Compensation Expense EmployeeStockOwnershipPlanESOPCompensationExpense	9923000	usd
CY2021	us-gaap	Employee Stock Ownership Plan Esop Compensation Expense EmployeeStockOwnershipPlanESOPCompensationExpense	9408000	usd
CY2023	us-gaap	Gain Loss On Sale Of Notes Receivable GainLossOnSaleOfNotesReceivable	-2738000	usd
CY2022	us-gaap	Gain Loss On Sale Of Notes Receivable GainLossOnSaleOfNotesReceivable	0	usd
CY2021	us-gaap	Gain Loss On Sale Of Notes Receivable GainLossOnSaleOfNotesReceivable	0	usd
CY2023	ebc	Proceeds From Sale Of Loan Transferred To Held For Sale Operating Activities ProceedsFromSaleOfLoanTransferredToHeldForSaleOperatingActivities	22126000	usd
CY2022	ebc	Proceeds From Sale Of Loan Transferred To Held For Sale Operating Activities ProceedsFromSaleOfLoanTransferredToHeldForSaleOperatingActivities	0	usd
CY2021	ebc	Proceeds From Sale Of Loan Transferred To Held For Sale Operating Activities ProceedsFromSaleOfLoanTransferredToHeldForSaleOperatingActivities	0	usd
CY2023	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	25000	usd
CY2022	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	17000	usd
CY2021	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	-106000	usd
CY2023	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	-3403000	usd
CY2022	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	3354000	usd
CY2021	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	47000	usd
CY2023	us-gaap	Increase Decrease In Prepaid Expense IncreaseDecreaseInPrepaidExpense	-4260000	usd
CY2022	us-gaap	Increase Decrease In Prepaid Expense IncreaseDecreaseInPrepaidExpense	-4338000	usd
CY2021	us-gaap	Increase Decrease In Prepaid Expense IncreaseDecreaseInPrepaidExpense	-1130000	usd
CY2023	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	14394000	usd
CY2022	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-5431000	usd
CY2021	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-62380000	usd
CY2023	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	39035000	usd
CY2022	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-52800000	usd
CY2021	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-16132000	usd
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	385441000	usd
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	213119000	usd
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	169155000	usd
CY2023	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	-123749000	usd
CY2022	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	16823000	usd
CY2021	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	5335000	usd
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	261692000	usd
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	229942000	usd
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	174490000	usd
CY2023	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	1899724000	usd
CY2022	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	431193000	usd
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	23798000	usd
CY2023	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	423885000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1049522000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	939575000	usd
CY2023	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	0	usd
CY2022	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	740770000	usd
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	3323893000	usd
CY2023	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	27397000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	17399000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	0	usd
CY2023	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	usd
CY2022	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	493678000	usd
CY2021	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	usd
CY2023	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	286309000	usd
CY2022	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	63715000	usd
CY2021	us-gaap	Proceeds From Sale Of Federal Home Loan Bank Stock ProceedsFromSaleOfFederalHomeLoanBankStock	6692000	usd
CY2023	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	250850000	usd
CY2022	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	94174000	usd
CY2021	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	2101000	usd
CY2023	ebc	Contributions To Low Income Housing Tax Credit Investments ContributionsToLowIncomeHousingTaxCreditInvestments	-36939000	usd
CY2022	ebc	Contributions To Low Income Housing Tax Credit Investments ContributionsToLowIncomeHousingTaxCreditInvestments	-19487000	usd
CY2021	ebc	Contributions To Low Income Housing Tax Credit Investments ContributionsToLowIncomeHousingTaxCreditInvestments	-11379000	usd
CY2023	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	720000	usd
CY2022	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	788000	usd
CY2021	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	2519000	usd
CY2023	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	362000	usd
CY2022	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	1170000	usd
CY2021	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	337000	usd
CY2023	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	0	usd
CY2022	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	20446000	usd
CY2021	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	0	usd
CY2022	ebc	Proceeds From Payments For Outstanding Loans ProceedsFromPaymentsForOutstandingLoans	926255000	usd
CY2021	ebc	Proceeds From Payments For Outstanding Loans ProceedsFromPaymentsForOutstandingLoans	-380807000	usd
CY2023	us-gaap	Proceeds From Sale Of Finance Receivables ProceedsFromSaleOfFinanceReceivables	189296000	usd
CY2022	us-gaap	Proceeds From Sale Of Finance Receivables ProceedsFromSaleOfFinanceReceivables	0	usd
CY2021	us-gaap	Proceeds From Sale Of Finance Receivables ProceedsFromSaleOfFinanceReceivables	0	usd
CY2023	us-gaap	Payments To Acquire Finance Receivables PaymentsToAcquireFinanceReceivables	31980000	usd
CY2022	us-gaap	Payments To Acquire Finance Receivables PaymentsToAcquireFinanceReceivables	380234000	usd
CY2021	us-gaap	Payments To Acquire Finance Receivables PaymentsToAcquireFinanceReceivables	0	usd
CY2023	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	usd
CY2022	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	usd
CY2021	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	9085000	usd
CY2023	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	8140000	usd
CY2022	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	8627000	usd
CY2021	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	5728000	usd
CY2023	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	0	usd
CY2022	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	17313000	usd
CY2021	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	21981000	usd
CY2023	us-gaap	Proceeds From Sale Of Other Real Estate ProceedsFromSaleOfOtherRealEstate	0	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	125000	usd
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities Continuing Operations NetCashProvidedByUsedInInvestingActivitiesContinuingOperations	1911760000	usd
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities Continuing Operations NetCashProvidedByUsedInInvestingActivitiesContinuingOperations	-1063255000	usd
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities Continuing Operations NetCashProvidedByUsedInInvestingActivitiesContinuingOperations	-1981390000	usd
CY2023	us-gaap	Cash Provided By Used In Investing Activities Discontinued Operations CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations	488505000	usd
CY2022	us-gaap	Cash Provided By Used In Investing Activities Discontinued Operations CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations	-13400000	usd
CY2021	us-gaap	Cash Provided By Used In Investing Activities Discontinued Operations CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations	-4354000	usd
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	2400265000	usd
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1076655000	usd
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1985744000	usd
CY2023	us-gaap	Increase Decrease In Demand Deposits IncreaseDecreaseInDemandDeposits	-2462797000	usd
CY2022	us-gaap	Increase Decrease In Demand Deposits IncreaseDecreaseInDemandDeposits	-1751953000	usd
CY2021	us-gaap	Increase Decrease In Demand Deposits IncreaseDecreaseInDemandDeposits	1155868000	usd
CY2023	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	1084655000	usd
CY2022	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	1098001000	usd
CY2021	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	-58144000	usd
CY2023	ebc	Proceeds From Repayments Of Borrowed Funds ProceedsFromRepaymentsOfBorrowedFunds	-692612000	usd
CY2022	ebc	Proceeds From Repayments Of Borrowed Funds ProceedsFromRepaymentsOfBorrowedFunds	706550000	usd
CY2021	ebc	Proceeds From Repayments Of Borrowed Funds ProceedsFromRepaymentsOfBorrowedFunds	2580000	usd
CY2023	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	usd
CY2022	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	usd
CY2021	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	36277000	usd
CY2023	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	usd
CY2022	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	201618000	usd
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	23224000	usd
CY2023	us-gaap	Payments Of Dividends PaymentsOfDividends	66671000	usd
CY2022	us-gaap	Payments Of Dividends PaymentsOfDividends	65886000	usd
CY2021	us-gaap	Payments Of Dividends PaymentsOfDividends	51564000	usd
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities Continuing Operations NetCashProvidedByUsedInFinancingActivitiesContinuingOperations	-2137425000	usd
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities Continuing Operations NetCashProvidedByUsedInFinancingActivitiesContinuingOperations	-214906000	usd
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities Continuing Operations NetCashProvidedByUsedInFinancingActivitiesContinuingOperations	989239000	usd
CY2023	us-gaap	Cash Provided By Used In Financing Activities Discontinued Operations CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations	-961000	usd
CY2022	us-gaap	Cash Provided By Used In Financing Activities Discontinued Operations CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations	-668000	usd
CY2021	us-gaap	Cash Provided By Used In Financing Activities Discontinued Operations CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations	-263000	usd
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-2138386000	usd
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-215574000	usd
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	988976000	usd
CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	523571000	usd
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-1062287000	usd
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-822278000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	169505000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1231792000	usd
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	2054070000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	693076000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	169505000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1231792000	usd
CY2023	us-gaap	Interest Paid Net InterestPaidNet	231765000	usd
CY2022	us-gaap	Interest Paid Net InterestPaidNet	35241000	usd
CY2021	us-gaap	Interest Paid Net InterestPaidNet	5354000	usd
CY2023	us-gaap	Income Taxes Paid IncomeTaxesPaid	65921000	usd
CY2022	us-gaap	Income Taxes Paid IncomeTaxesPaid	41751000	usd
CY2021	us-gaap	Income Taxes Paid IncomeTaxesPaid	43299000	usd
CY2023	ebc	Net Increase In Capital Commitments Relating To Low Income Housing Tax Credit Projects NetIncreaseInCapitalCommitmentsRelatingToLowIncomeHousingTaxCreditProjects	102001000	usd
CY2022	ebc	Net Increase In Capital Commitments Relating To Low Income Housing Tax Credit Projects NetIncreaseInCapitalCommitmentsRelatingToLowIncomeHousingTaxCreditProjects	55233000	usd
CY2021	ebc	Net Increase In Capital Commitments Relating To Low Income Housing Tax Credit Projects NetIncreaseInCapitalCommitmentsRelatingToLowIncomeHousingTaxCreditProjects	28291000	usd
CY2023	ebc	Maturity Of Acquired Securities Sold Under Agreements To Repurchase Noncash MaturityOfAcquiredSecuritiesSoldUnderAgreementsToRepurchaseNoncash	0	usd
CY2022	ebc	Maturity Of Acquired Securities Sold Under Agreements To Repurchase Noncash MaturityOfAcquiredSecuritiesSoldUnderAgreementsToRepurchaseNoncash	0	usd
CY2021	ebc	Maturity Of Acquired Securities Sold Under Agreements To Repurchase Noncash MaturityOfAcquiredSecuritiesSoldUnderAgreementsToRepurchaseNoncash	274982000	usd
CY2023	ebc	Net Increase Decrease In Operating Lease Right Of Use Assets And Operating Lease Liabilities Relating To Lease Remeasurements And Modifications NetIncreaseDecreaseInOperatingLeaseRightOfUseAssetsAndOperatingLeaseLiabilitiesRelatingToLeaseRemeasurementsAndModifications	3881000	usd
CY2022	ebc	Net Increase Decrease In Operating Lease Right Of Use Assets And Operating Lease Liabilities Relating To Lease Remeasurements And Modifications NetIncreaseDecreaseInOperatingLeaseRightOfUseAssetsAndOperatingLeaseLiabilitiesRelatingToLeaseRemeasurementsAndModifications	14836000	usd
CY2021	ebc	Net Increase Decrease In Operating Lease Right Of Use Assets And Operating Lease Liabilities Relating To Lease Remeasurements And Modifications NetIncreaseDecreaseInOperatingLeaseRightOfUseAssetsAndOperatingLeaseLiabilitiesRelatingToLeaseRemeasurementsAndModifications	0	usd
CY2023	us-gaap	Use Of Estimates UseOfEstimates	<div style="margin-top:12pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Use of Estimates</span></div><div style="margin-top:6pt;text-indent:54pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">In preparing the Consolidated Financial Statements in conformity with GAAP, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheets and income and expenses for the periods reported. Actual results could differ from those estimates based on changing conditions, including economic conditions and future events. Material estimates that are particularly susceptible to change relate to the determination of the allowance for loan losses, valuation and fair value measurements, allowance for credit losses on investment securities, the liabilities for benefit obligations (particularly pensions), the provision for income taxes and impairment of goodwill and the core deposit intangible.</span></div>
CY2023Q4	us-gaap	Restricted Cash RestrictedCash	11500000	usd
CY2022Q4	us-gaap	Restricted Cash RestrictedCash	1000000	usd
CY2022Q1	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2022Q4	us-gaap	Other Real Estate OtherRealEstate	0	usd
CY2023Q4	us-gaap	Other Real Estate OtherRealEstate	0	usd
CY2023	us-gaap	Number Of Reporting Units NumberOfReportingUnits	1	reporting_unit
CY2023	ebc	Defined Benefit Plan Age Requirement DefinedBenefitPlanAgeRequirement	P21Y
CY2023	ebc	Defined Benefit Plan Service Requirement DefinedBenefitPlanServiceRequirement	P1Y
CY2023	ebc	Defined Benefit Plan Service Requirement For Full Vesting For Individuals Employed On Or Before October211989 DefinedBenefitPlanServiceRequirementForFullVestingForIndividualsEmployedOnOrBeforeOctober211989	P3Y
CY2023	ebc	Defined Benefit Plan Service Requirement For Full Vesting For Individuals Employed Subsequent To October311989 DefinedBenefitPlanServiceRequirementForFullVestingForIndividualsEmployedSubsequentToOctober311989	P5Y
CY2023	ebc	Number Of Deferred Compensation Plans NumberOfDeferredCompensationPlans	3	plan
CY2023	us-gaap	Debt Securities Available For Sale Accrued Interest Writeoff DebtSecuritiesAvailableForSaleAccruedInterestWriteoff	0	usd
CY2023	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	1	segment
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	5161904000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	172000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	754555000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	4407521000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	7825435000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	9000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	1134666000	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 Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	6690778000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Accrued Interest After Allowance For Credit Loss DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss	9200000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Accrued Interest After Allowance For Credit Loss DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss	12900000	usd
CY2022	us-gaap	Debt Securities Available For Sale Accrued Interest Writeoff DebtSecuritiesAvailableForSaleAccruedInterestWriteoff	0	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	0	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	1775000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	1166000	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	333170000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	4932000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	0	usd
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-333170000	usd
CY2022	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-3157000	usd
CY2021	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	1166000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	736
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	269000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	27821000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	754286000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	4346529000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	754555000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	4374350000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	802
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	98038000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	968376000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	1036628000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	5719149000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	1134666000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	6687525000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	449721000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	0	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	44899000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	404822000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	476647000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	0	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	53421000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	423226000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityAccruedInterestAfterAllowanceForCreditLoss	900000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityAccruedInterestAfterAllowanceForCreditLoss	1000000	usd
CY2022	us-gaap	Debt Securities Held To Maturity Accrued Interest Writeoff DebtSecuritiesHeldToMaturityAccruedInterestWriteoff	0	usd
CY2023	us-gaap	Debt Securities Held To Maturity Accrued Interest Writeoff DebtSecuritiesHeldToMaturityAccruedInterestWriteoff	0	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	213000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	209000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	651654000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	603469000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	446531000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	391693000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	4063506000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	3412150000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	5161904000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	4407521000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date Year One DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateYearOne	0	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue	0	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year One Through Five DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFive	80014000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	72952000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year5 Through10 DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear5Through10	114955000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	101551000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year10 DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear10	254752000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue	230319000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDate	449721000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	404822000	usd
CY2023Q4	ebc	Debt Securities Amortized Cost Maturity Allocated And Single Maturity Date Year One DebtSecuritiesAmortizedCostMaturityAllocatedAndSingleMaturityDateYearOne	213000	usd
CY2023Q4	ebc	Debt Securities Fair Value Maturity Allocated And Single Maturity Date Year One DebtSecuritiesFairValueMaturityAllocatedAndSingleMaturityDateYearOne	209000	usd
CY2023Q4	ebc	Debt Securities Amortized Cost After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year One Through Five DebtSecuritiesAmortizedCostAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFive	731668000	usd
CY2023Q4	ebc	Debt Securities Fair Value Maturity Allocated And Single Maturity Date After Year One Through Five DebtSecuritiesFairValueMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFive	676421000	usd
CY2023Q4	ebc	Debt Securities Amortized Cost After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year Five Through Ten DebtSecuritiesAmortizedCostAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYearFiveThroughTen	561486000	usd
CY2023Q4	ebc	Debt Securities Fair Value Maturity Allocated And Single Maturity Date After Year5 Through10 DebtSecuritiesFairValueMaturityAllocatedAndSingleMaturityDateAfterYear5Through10	493244000	usd
CY2023Q4	ebc	Debt Securities Amortized Cost After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year10 DebtSecuritiesAmortizedCostAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear10	4318258000	usd
CY2023Q4	ebc	Debt Securities Fair Value Maturity Allocated And Single Maturity Date After Year10 DebtSecuritiesFairValueMaturityAllocatedAndSingleMaturityDateAfterYear10	3642469000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale And Held To Maturity Amortized Cost After Allowance For Credit Loss DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss	5611625000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale And Held To Maturity Fair Value DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue	4812343000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	1512000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	1494000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	1211778000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	1074080000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	1643641000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	1430761000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	4968504000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	4184443000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	7825435000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	6690778000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date Year One DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateYearOne	0	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue	0	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year One Through Five DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFive	0	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	0	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year5 Through10 DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear5Through10	200154000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	176883000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year10 DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear10	276493000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue	246343000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDate	476647000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	423226000	usd
CY2022Q4	ebc	Debt Securities Amortized Cost Maturity Allocated And Single Maturity Date Year One DebtSecuritiesAmortizedCostMaturityAllocatedAndSingleMaturityDateYearOne	1512000	usd
CY2022Q4	ebc	Debt Securities Fair Value Maturity Allocated And Single Maturity Date Year One DebtSecuritiesFairValueMaturityAllocatedAndSingleMaturityDateYearOne	1494000	usd
CY2022Q4	ebc	Debt Securities Amortized Cost After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year One Through Five DebtSecuritiesAmortizedCostAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFive	1211778000	usd
CY2022Q4	ebc	Debt Securities Fair Value Maturity Allocated And Single Maturity Date After Year One Through Five DebtSecuritiesFairValueMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFive	1074080000	usd
CY2022Q4	ebc	Debt Securities Amortized Cost After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year Five Through Ten DebtSecuritiesAmortizedCostAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYearFiveThroughTen	1843795000	usd
CY2022Q4	ebc	Debt Securities Fair Value Maturity Allocated And Single Maturity Date After Year5 Through10 DebtSecuritiesFairValueMaturityAllocatedAndSingleMaturityDateAfterYear5Through10	1607644000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	779687000	usd
CY2022Q4	ebc	Debt Securities Amortized Cost After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year10 DebtSecuritiesAmortizedCostAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear10	5244997000	usd
CY2022Q4	ebc	Debt Securities Fair Value Maturity Allocated And Single Maturity Date After Year10 DebtSecuritiesFairValueMaturityAllocatedAndSingleMaturityDateAfterYear10	4430786000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale And Held To Maturity Amortized Cost After Allowance For Credit Loss DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss	8302082000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale And Held To Maturity Fair Value DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue	7114004000	usd
CY2023Q4	us-gaap	Deposit Liabilities Collateral Issued Financial Instruments DepositLiabilitiesCollateralIssuedFinancialInstruments	615700000	usd
CY2022Q4	us-gaap	Deposit Liabilities Collateral Issued Financial Instruments DepositLiabilitiesCollateralIssuedFinancialInstruments	437900000	usd
CY2023Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	13973428000	usd
CY2022Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	13575531000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	148993000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	142211000	usd
CY2023Q4	us-gaap	Financing Receivable Unamortized Loan Commitment Origination Fee And Premium Discount FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount	-25068000	usd
CY2022Q4	us-gaap	Financing Receivable Unamortized Loan Commitment Origination Fee And Premium Discount FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount	-13003000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	13799367000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	13420317000	usd
CY2023Q4	us-gaap	Financing Receivable Accrued Interest Before Allowance For Credit Loss FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss	53900000	usd
CY2022Q4	us-gaap	Financing Receivable Accrued Interest Before Allowance For Credit Loss FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss	45200000	usd
CY2023Q4	us-gaap	Credit Derivative Maximum Exposure Undiscounted CreditDerivativeMaximumExposureUndiscounted	100000000	usd
CY2023Q4	us-gaap	Participating Mortgage Loans Mortgage Obligations Amount ParticipatingMortgageLoansMortgageObligationsAmount	77200000	usd
CY2022Q4	us-gaap	Participating Mortgage Loans Mortgage Obligations Amount ParticipatingMortgageLoansMortgageObligationsAmount	84000000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	142211000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	2965000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	20052000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	148993000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	4831000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	4244000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	17925000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	142211000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Period Increase Decrease FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossPeriodIncreaseDecrease	6800000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	149000000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	142200000	usd
CY2023	ebc	Financing Receivable Allowance For Credit Loss To Outstanding Percent Period Increase Decrease FinancingReceivableAllowanceForCreditLossToOutstandingPercentPeriodIncreaseDecrease	2
CY2023Q4	srt	Financing Receivable Allowance For Credit Loss To Outstanding Percent FinancingReceivableAllowanceForCreditLossToOutstandingPercent	0.0107
CY2022Q4	srt	Financing Receivable Allowance For Credit Loss To Outstanding Percent FinancingReceivableAllowanceForCreditLossToOutstandingPercent	0.0105
CY2023	ebc	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff Period Increase Decrease FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffPeriodIncreaseDecrease	10300000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	15100000	usd
CY2022	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	4800000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	1685825000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	3116426000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	2223220000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	1459559000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	921574000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	2846088000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	1674790000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving Converted To Term Loan FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan	20878000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	13948360000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	3481250000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	2447552000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	1630538000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	1094274000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	2496108000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	1614995000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving Converted To Term Loan FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan	18124000	usd
CY2023	ebc	Consumer Credit Exposures Period Past Due Required To Classify Loans As Special Mention Maximum ConsumerCreditExposuresPeriodPastDueRequiredToClassifyLoansAsSpecialMentionMaximum	P90D
CY2023	ebc	Consumer Credit Exposures Period Past Due Required To Classify Loans As Special Mention Maximum ConsumerCreditExposuresPeriodPastDueRequiredToClassifyLoansAsSpecialMentionMaximum	P90D
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	13948360000	usd
CY2022Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	13562528000	usd
CY2023Q4	ebc	Financing Receivable Nonaccrual With Allowance FinancingReceivableNonaccrualWithAllowance	35995000	usd
CY2023Q4	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	16562000	usd
CY2023Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	52557000	usd
CY2022Q4	ebc	Financing Receivable Nonaccrual With Allowance FinancingReceivableNonaccrualWithAllowance	26244000	usd
CY2022Q4	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	12360000	usd
CY2022Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	38604000	usd
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	19363000	usd
CY2023	us-gaap	Financing Receivable Modification To Total Financing Receivables Excluding Accrued Interest Percent FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent	0.0014
CY2023	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	19363000	usd
CY2023Q4	us-gaap	Investment Owned At Cost InvestmentOwnedAtCost	1579059000	usd
CY2023Q4	ebc	Non Performing Loan Percentage NonPerformingLoanPercentage	0.0000
CY2023	us-gaap	Derecognized Assets Securitized Or Assetbacked Financing Arrangement Assets And Any Other Financial Assets Managed Together Net Credit Losses During Period DerecognizedAssetsSecuritizedOrAssetbackedFinancingArrangementAssetsAndAnyOtherFinancialAssetsManagedTogetherNetCreditLossesDuringPeriod	22000	usd
CY2022Q4	us-gaap	Investment Owned At Cost InvestmentOwnedAtCost	1542358000	usd
CY2022Q4	ebc	Non Performing Loan Percentage NonPerformingLoanPercentage	0.0055
CY2022	us-gaap	Derecognized Assets Securitized Or Assetbacked Financing Arrangement Assets And Any Other Financial Assets Managed Together Net Credit Losses During Period DerecognizedAssetsSecuritizedOrAssetbackedFinancingArrangementAssetsAndAnyOtherFinancialAssetsManagedTogetherNetCreditLossesDuringPeriod	3000	usd
CY2022	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	257	loan
CY2022Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	48185000	usd
CY2022Q4	ebc	Investment Recorded Represented By Troubled Debt Restructuring In The Current Period InvestmentRecordedRepresentedByTroubledDebtRestructuringInTheCurrentPeriod	11000000	usd
CY2022Q4	ebc	Amount Of Specific Reserve Associated With Troubled Debt Restructuring AmountOfSpecificReserveAssociatedWithTroubledDebtRestructuring	1800000	usd
CY2022	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	51	contract
CY2022	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	12571000	usd
CY2022	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	12590000	usd
CY2021	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	5	contract
CY2021	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	798000	usd
CY2021	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	798000	usd
CY2022	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	12590000	usd
CY2021	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	798000	usd
CY2022	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	1	loan
CY2022	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	1000000	usd
CY2021	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	loan
CY2022	ebc	Amounts Charged Off On Td Rs AmountsChargedOffOnTDRs	0	usd
CY2021	ebc	Amounts Charged Off On Td Rs AmountsChargedOffOnTDRs	0	usd
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	113031000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	9002000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	3444000	usd
CY2021	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	-9686000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	97787000	usd
CY2021	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	34637000	usd
CY2021	us-gaap	Impaired Financing Receivable With No Related Allowance Interest Income Accrual Method ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod	956000	usd
CY2021	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	35673000	usd
CY2021	us-gaap	Impaired Financing Receivable With Related Allowance Interest Income Accrual Method ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod	596000	usd
CY2021	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	70310000	usd
CY2021	us-gaap	Impaired Financing Receivable Interest Income Accrual Method ImpairedFinancingReceivableInterestIncomeAccrualMethod	1552000	usd
CY2020Q4	us-gaap	Certain Loans Acquired In Transfer Accretable Yield CertainLoansAcquiredInTransferAccretableYield	2495000	usd
CY2021	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Additions CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAdditions	8896000	usd
CY2021	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	1194000	usd
CY2021	ebc	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Other Cash Flow Changes CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesOtherCashFlowChanges	-1475000	usd
CY2021	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications To From Nonaccretable Difference CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsToFromNonaccretableDifference	1649000	usd
CY2021Q4	us-gaap	Certain Loans Acquired In Transfer Accretable Yield CertainLoansAcquiredInTransferAccretableYield	10371000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	155728000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	154865000	usd
CY2023Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	95595000	usd
CY2022Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	92372000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	60133000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	62493000	usd
CY2023Q4	us-gaap	Assets Held For Sale Not Part Of Disposal Group AssetsHeldForSaleNotPartOfDisposalGroup	0	usd
CY2022Q4	us-gaap	Assets Held For Sale Not Part Of Disposal Group AssetsHeldForSaleNotPartOfDisposalGroup	0	usd
CY2023Q4	ebc	Property Plant And Equipment Including Assets Held For Sale Not Part Of Disposal Group PropertyPlantAndEquipmentIncludingAssetsHeldForSaleNotPartOfDisposalGroup	60133000	usd
CY2022Q4	ebc	Property Plant And Equipment Including Assets Held For Sale Not Part Of Disposal Group PropertyPlantAndEquipmentIncludingAssetsHeldForSaleNotPartOfDisposalGroup	62493000	usd
CY2023	us-gaap	Depreciation Depreciation	10500000	usd
CY2022	us-gaap	Depreciation Depreciation	10700000	usd
CY2021	us-gaap	Depreciation Depreciation	11600000	usd
CY2023	ebc	Number Of Properties Transferred To Held For Sale NumberOfPropertiesTransferredToHeldForSale	0	property
CY2023	ebc	Number Of Properties Sold NumberOfPropertiesSold	0	property
CY2022	ebc	Number Of Properties Transferred To Held For Sale NumberOfPropertiesTransferredToHeldForSale	0	property
CY2022	ebc	Number Of Properties Sold NumberOfPropertiesSold	5	property
CY2022	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	17300000	usd
CY2022	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	1400000	usd
CY2021	ebc	Premises Transferred To Held For Sale PremisesTransferredToHeldForSale	37600000	usd
CY2021	ebc	Number Of Properties Transferred To Held For Sale NumberOfPropertiesTransferredToHeldForSale	5	property
CY2021	ebc	Gain Loss On Properties Transferred To Held For Sale GainLossOnPropertiesTransferredToHeldForSale	-1200000	usd
CY2021	ebc	Number Of Properties Sold NumberOfPropertiesSold	3	property
CY2021	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	22000000	usd
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	50641000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	48817000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	55617000	usd
CY2022Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	52105000	usd
CY2023	us-gaap	Operating Lease Cost OperatingLeaseCost	12439000	usd
CY2022	us-gaap	Operating Lease Cost OperatingLeaseCost	12716000	usd
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	12559000	usd
CY2023	ebc	Finance Lease Cost FinanceLeaseCost	338000	usd
CY2022	ebc	Finance Lease Cost FinanceLeaseCost	309000	usd
CY2021	ebc	Finance Lease Cost FinanceLeaseCost	160000	usd
CY2023	us-gaap	Variable Lease Cost VariableLeaseCost	2766000	usd
CY2022	us-gaap	Variable Lease Cost VariableLeaseCost	2547000	usd
CY2021	us-gaap	Variable Lease Cost VariableLeaseCost	2012000	usd
CY2023	us-gaap	Lease Cost LeaseCost	15543000	usd
CY2022	us-gaap	Lease Cost LeaseCost	15572000	usd
CY2021	us-gaap	Lease Cost LeaseCost	14731000	usd
CY2023	ebc	Finance Lease Principal Payments And Operating Lease Payments FinanceLeasePrincipalPaymentsAndOperatingLeasePayments	13300000	usd
CY2022	ebc	Finance Lease Principal Payments And Operating Lease Payments FinanceLeasePrincipalPaymentsAndOperatingLeasePayments	15200000	usd
CY2021	ebc	Finance Lease Principal Payments And Operating Lease Payments FinanceLeasePrincipalPaymentsAndOperatingLeasePayments	13600000	usd
CY2023Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P8Y3M3D
CY2022Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P7Y3M
CY2023Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0376
CY2022Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0262
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	11506000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	8504000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	7143000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	5609000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	5886000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	27770000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	66418000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	10801000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	55617000	usd
CY2023	ebc	Operating Lease Number Of Extensions Not Exercised OperatingLeaseNumberOfExtensionsNotExercised	4	extension
CY2023	ebc	Operating Lease Number Of Extensions Exercised OperatingLeaseNumberOfExtensionsExercised	10	extension
CY2023	ebc	Number Of Leases Terminated NumberOfLeasesTerminated	1	lease
CY2023	ebc	Net Increase Decrease In Operating Lease Right Of Use Assets And Operating Lease Liabilities Relating To Lease Remeasurements NetIncreaseDecreaseInOperatingLeaseRightOfUseAssetsAndOperatingLeaseLiabilitiesRelatingToLeaseRemeasurements	2400000	usd
CY2023	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	400000	usd
CY2022	ebc	Operating Lease Number Of Extensions Not Exercised OperatingLeaseNumberOfExtensionsNotExercised	2	extension
CY2022	ebc	Operating Lease Number Of Extensions Exercised OperatingLeaseNumberOfExtensionsExercised	2	extension
CY2022	ebc	Number Of Leases Terminated NumberOfLeasesTerminated	4	lease
CY2022	ebc	Net Increase Decrease In Operating Lease Right Of Use Assets And Operating Lease Liabilities Relating To Lease Remeasurements NetIncreaseDecreaseInOperatingLeaseRightOfUseAssetsAndOperatingLeaseLiabilitiesRelatingToLeaseRemeasurements	-14400000	usd
CY2022	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	600000	usd
CY2023Q4	us-gaap	Goodwill Goodwill	557635000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	557635000	usd
CY2023Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	566205000	usd
CY2022Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	568009000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	557635000	usd
CY2021Q4	us-gaap	Goodwill Goodwill	557635000	usd
CY2023	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	0	usd
CY2022	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	0	usd
CY2023Q4	us-gaap	Goodwill Goodwill	557635000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	557635000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	11633000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	3063000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	8570000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	15969000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	5595000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	10374000	usd
CY2023	us-gaap	Number Of Reporting Units NumberOfReportingUnits	1	reporting_unit
CY2023	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1800000	usd
CY2022	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1200000	usd
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	200000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	2017000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	2017000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	2017000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	2017000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	502000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	8570000	usd
CY2023Q4	us-gaap	Demand Deposit Accounts DemandDepositAccounts	5162218000	usd
CY2022Q4	us-gaap	Demand Deposit Accounts DemandDepositAccounts	6240637000	usd
CY2023Q4	us-gaap	Interest Bearing Domestic Deposit Checking InterestBearingDomesticDepositChecking	3737361000	usd
CY2022Q4	us-gaap	Interest Bearing Domestic Deposit Checking InterestBearingDomesticDepositChecking	4568122000	usd
CY2023Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	1323126000	usd
CY2022Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	1831123000	usd
CY2023Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	4664475000	usd
CY2022Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	4710095000	usd
CY2023Q4	us-gaap	Time Deposits TimeDeposits	2709037000	usd
CY2022Q4	us-gaap	Time Deposits TimeDeposits	1624382000	usd
CY2023Q4	us-gaap	Deposits Deposits	17596217000	usd
CY2022Q4	us-gaap	Deposits Deposits	18974359000	usd
CY2023Q4	us-gaap	Bank Overdrafts BankOverdrafts	2400000	usd
CY2022Q4	us-gaap	Bank Overdrafts BankOverdrafts	2300000	usd
CY2023Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	2683364000	usd
CY2023Q4	us-gaap	Time Deposits Weighted Average Interest Rate Maturities Year One TimeDepositsWeightedAverageInterestRateMaturitiesYearOne	0.991
CY2023Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	15484000	usd
CY2023Q4	us-gaap	Time Deposits Weighted Average Interest Rate Maturities Year Two TimeDepositsWeightedAverageInterestRateMaturitiesYearTwo	0.006
CY2023Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	5630000	usd
CY2023Q4	us-gaap	Time Deposits Weighted Average Interest Rate Maturities Year Three TimeDepositsWeightedAverageInterestRateMaturitiesYearThree	0.002
CY2023Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	2940000	usd
CY2023Q4	us-gaap	Time Deposits Weighted Average Interest Rate Maturities Year Four TimeDepositsWeightedAverageInterestRateMaturitiesYearFour	0.001
CY2023Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	1586000	usd
CY2023Q4	us-gaap	Time Deposits Weighted Average Interest Rate Maturities Year Five TimeDepositsWeightedAverageInterestRateMaturitiesYearFive	0.001
CY2023Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	33000	usd
CY2023Q4	us-gaap	Time Deposits Weighted Average Interest Rate Maturities Greater Than Five Years TimeDepositsWeightedAverageInterestRateMaturitiesGreaterThanFiveYears	0.000
CY2023Q4	us-gaap	Time Deposits TimeDeposits	2709037000	usd
CY2023Q4	us-gaap	Weighted Average Rate Domestic Deposit Certificates Of Deposit WeightedAverageRateDomesticDepositCertificatesOfDeposit	1.000
CY2023Q4	us-gaap	Time Deposits At Or Above Fdic Insurance Limit TimeDepositsAtOrAboveFDICInsuranceLimit	867600000	usd
CY2022Q4	us-gaap	Time Deposits At Or Above Fdic Insurance Limit TimeDepositsAtOrAboveFDICInsuranceLimit	239100000	usd
CY2023Q4	ebc	Time Deposits Brokered TimeDepositsBrokered	50000000	usd
CY2022Q4	ebc	Time Deposits Brokered TimeDepositsBrokered	928600000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	95000	usd
CY2022Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	691297000	usd
CY2023Q4	ebc	Escrow Deposits Of Borrowers EscrowDepositsOfBorrowers	21978000	usd
CY2022Q4	ebc	Escrow Deposits Of Borrowers EscrowDepositsOfBorrowers	22314000	usd
CY2023Q4	ebc	Interest Rate Swap Collateral Funds InterestRateSwapCollateralFunds	8500000	usd
CY2022Q4	ebc	Interest Rate Swap Collateral Funds InterestRateSwapCollateralFunds	14430000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	17643000	usd
CY2022Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	12787000	usd
CY2023Q4	us-gaap	Debt Longterm And Shortterm Combined Amount DebtLongtermAndShorttermCombinedAmount	48216000	usd
CY2022Q4	us-gaap	Debt Longterm And Shortterm Combined Amount DebtLongtermAndShorttermCombinedAmount	740828000	usd
CY2023	us-gaap	Interest Expense Borrowings InterestExpenseBorrowings	19975000	usd
CY2022	us-gaap	Interest Expense Borrowings InterestExpenseBorrowings	8506000	usd
CY2021	us-gaap	Interest Expense Borrowings InterestExpenseBorrowings	165000	usd
CY2023	us-gaap	Proceeds From Dividends Received ProceedsFromDividendsReceived	2000000	usd
CY2022	us-gaap	Proceeds From Dividends Received ProceedsFromDividendsReceived	300000	usd
CY2021	us-gaap	Proceeds From Dividends Received ProceedsFromDividendsReceived	200000	usd
CY2023	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-62689000	usd
CY2022	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	186511000	usd
CY2021	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	145531000	usd
CY2023	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	294866000	usd
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	13248000	usd
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	9134000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	232177000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	199759000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	154665000	usd
CY2023	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	175814954	shares
CY2022	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	179529613	shares
CY2021	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	186713020	shares
CY2023	us-gaap	Weighted Average Number Of Shares Employee Stock Ownership Plan Shares Not Committed To Be Released WeightedAverageNumberOfSharesEmployeeStockOwnershipPlanSharesNotCommittedToBeReleased	13521934	shares
CY2022	us-gaap	Weighted Average Number Of Shares Employee Stock Ownership Plan Shares Not Committed To Be Released WeightedAverageNumberOfSharesEmployeeStockOwnershipPlanSharesNotCommittedToBeReleased	14019256	shares
CY2021	us-gaap	Weighted Average Number Of Shares Employee Stock Ownership Plan Shares Not Committed To Be Released WeightedAverageNumberOfSharesEmployeeStockOwnershipPlanSharesNotCommittedToBeReleased	14520684	shares
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	162293020	shares
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	165510357	shares
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	172192336	shares
CY2023	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	110077	shares
CY2022	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	138214	shares
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	59721	shares
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	162403097	shares
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	165648571	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	172252057	shares
CY2023	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.39
CY2022	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	36436000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.13
CY2021	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.85
CY2023	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	1.82
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.08
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.05
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.43
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.21
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.90
CY2023	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.39
CY2022	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.13
CY2021	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.85
CY2023	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	1.82
CY2022	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.08
CY2021	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.05
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.43
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.21
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.90
CY2023	ebc	Affordable Housing Investment Tax Credits AffordableHousingInvestmentTaxCredits	223400000	usd
CY2022	ebc	Affordable Housing Investment Tax Credits AffordableHousingInvestmentTaxCredits	131300000	usd
CY2023Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	221190000	usd
CY2022Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	128765000	usd
CY2023Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	149207000	usd
CY2022Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	84145000	usd
CY2023	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	11624000	usd
CY2022	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	9146000	usd
CY2021	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	6484000	usd
CY2023	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	9577000	usd
CY2022	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	7503000	usd
CY2021	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	5753000	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-63309000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	51719000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30464000	usd
CY2023	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.5025
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.2171
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.1732
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-63300000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	51700000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30500000	usd
CY2023Q1	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-23700000	usd
CY2023	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-39710000	usd
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	23923000	usd
CY2023	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	-5332000	usd
CY2022	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	10021000	usd
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	12204000	usd
CY2023	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	-45042000	usd
CY2022	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	46457000	usd
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	36127000	usd
CY2023	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	1219000	usd
CY2022	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-1028000	usd
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-7984000	usd
CY2023	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-19486000	usd
CY2022	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	6290000	usd
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	2321000	usd
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-18267000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	5262000	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-5663000	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-63309000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	51719000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30464000	usd
CY2023	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	-26458000	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.2100
CY2022	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	50029000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.2100
CY2021	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	36959000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.2100
CY2023	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	-19606000	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.1556
CY2022	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	12885000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.0541
CY2021	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	11475000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.0653
CY2023	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	0	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0
CY2022	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-700000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.0029
CY2021	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-11300000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.0642
CY2023	ebc	Effective Income Tax Rate Reconciliation Amortization Of Qualified Low Income Housing Investments Amount EffectiveIncomeTaxRateReconciliationAmortizationOfQualifiedLowIncomeHousingInvestmentsAmount	9577000	usd
CY2023	ebc	Effective Income Tax Rate Reconciliation Amortization Of Qualified Low Income Housing Investments Percent EffectiveIncomeTaxRateReconciliationAmortizationOfQualifiedLowIncomeHousingInvestmentsPercent	-0.0760
CY2022	ebc	Effective Income Tax Rate Reconciliation Amortization Of Qualified Low Income Housing Investments Amount EffectiveIncomeTaxRateReconciliationAmortizationOfQualifiedLowIncomeHousingInvestmentsAmount	7503000	usd
CY2022	ebc	Effective Income Tax Rate Reconciliation Amortization Of Qualified Low Income Housing Investments Percent EffectiveIncomeTaxRateReconciliationAmortizationOfQualifiedLowIncomeHousingInvestmentsPercent	0.0315
CY2021	ebc	Effective Income Tax Rate Reconciliation Amortization Of Qualified Low Income Housing Investments Amount EffectiveIncomeTaxRateReconciliationAmortizationOfQualifiedLowIncomeHousingInvestmentsAmount	5753000	usd
CY2021	ebc	Effective Income Tax Rate Reconciliation Amortization Of Qualified Low Income Housing Investments Percent EffectiveIncomeTaxRateReconciliationAmortizationOfQualifiedLowIncomeHousingInvestmentsPercent	0.0327
CY2023	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	9183000	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	-0.0729
CY2022	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	7300000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.0306
CY2021	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	6539000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.0372
CY2023	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	14161000	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	-0.1124
CY2022	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	10298000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.0432
CY2021	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	5665000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.0322
CY2023	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-3478000	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.0276
CY2022	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-400000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.0017
CY2021	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-219000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.0012
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-63309000	usd
CY2023	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.5025
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	51719000	usd
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.2171
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30464000	usd
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.1732
CY2023Q1	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-23700000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	193134000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	254502000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Loss Reserves DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLossReserves	45189000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Loss Reserves DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLossReserves	43686000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Derivative Instruments DeferredTaxAssetsDerivativeInstruments	12302000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Derivative Instruments DeferredTaxAssetsDerivativeInstruments	18192000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Deferred Gain On Sale Leaseback Transaction DeferredTaxAssetsDeferredGainOnSaleLeasebackTransaction	15664000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Deferred Gain On Sale Leaseback Transaction DeferredTaxAssetsDeferredGainOnSaleLeasebackTransaction	14858000	usd
CY2023Q4	ebc	Deferred Tax Asset Charitable Contribution Limitation Carryover DeferredTaxAssetCharitableContributionLimitationCarryover	4844000	usd
CY2022Q4	ebc	Deferred Tax Asset Charitable Contribution Limitation Carryover DeferredTaxAssetCharitableContributionLimitationCarryover	12273000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Investments DeferredTaxAssetsInvestments	7339000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Investments DeferredTaxAssetsInvestments	7918000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	10042000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	5426000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	4142000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	4287000	usd
CY2023Q4	ebc	Deferred Tax Assets Fair Value Adjustments DeferredTaxAssetsFairValueAdjustments	3455000	usd
CY2022Q4	ebc	Deferred Tax Assets Fair Value Adjustments DeferredTaxAssetsFairValueAdjustments	4009000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	0	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	354000	usd
CY2023Q4	ebc	Deferred Tax Assets Payment Protection Program Loans DeferredTaxAssetsPaymentProtectionProgramLoans	0	usd
CY2022Q4	ebc	Deferred Tax Assets Payment Protection Program Loans DeferredTaxAssetsPaymentProtectionProgramLoans	58000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	2061000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	2083000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	298172000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	367646000	usd
CY2023Q4	ebc	Deferred Tax Liabilities Amortization Of Intangibles DeferredTaxLiabilitiesAmortizationOfIntangibles	9660000	usd
CY2022Q4	ebc	Deferred Tax Liabilities Amortization Of Intangibles DeferredTaxLiabilitiesAmortizationOfIntangibles	16439000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	14284000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	13933000	usd
CY2023Q4	ebc	Deferred Tax Liabilities Partnerships DeferredTaxLiabilitiesPartnerships	1971000	usd
CY2022Q4	ebc	Deferred Tax Liabilities Partnerships DeferredTaxLiabilitiesPartnerships	2340000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Unrealized Gains On Trading Securities DeferredTaxLiabilitiesUnrealizedGainsOnTradingSecurities	3405000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Unrealized Gains On Trading Securities DeferredTaxLiabilitiesUnrealizedGainsOnTradingSecurities	938000	usd
CY2023Q4	ebc	Deferred Tax Liabilities Employee Benefits DeferredTaxLiabilitiesEmployeeBenefits	824000	usd
CY2022Q4	ebc	Deferred Tax Liabilities Employee Benefits DeferredTaxLiabilitiesEmployeeBenefits	0	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	1843000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	2033000	usd
CY2023Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	31987000	usd
CY2022Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	35683000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	266185000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	331963000	usd
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	12000000	usd
CY2020	ebc	Stock Issued During Period Value Charitable Donations StockIssuedDuringPeriodValueCharitableDonations	91300000	usd
CY2020	ebc	Charitable Cash Contribution CharitableCashContribution	3700000	usd
CY2021	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	-11300000	usd
CY2022Q4	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	-700000	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	5782000	usd
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	7923000	usd
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	usd
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	usd
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	usd
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	usd
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	7923000	usd
CY2023	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	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
CY2023	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	2279000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	2141000	usd
CY2021	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	0	usd
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	3503000	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	5782000	usd
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	7923000	usd
CY2023Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	3800000	usd
CY2023Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	1000000	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	1500000	usd
CY2023	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	500000	usd
CY2023	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	2300000	usd
CY2023	ebc	Tax Interest And Penalties Reduction Resulting From Lapse Of Applicable Statute Of Limitations TaxInterestAndPenaltiesReductionResultingFromLapseOfApplicableStatuteOfLimitations	700000	usd
CY2023Q4	us-gaap	Decrease In Unrecognized Tax Benefits Is Reasonably Possible DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible	1900000	usd
CY2023Q4	ebc	Decrease In Tax Interest And Penalties Is Reasonably Possible DecreaseInTaxInterestAndPenaltiesIsReasonablyPossible	800000	usd
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CY2022Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	0	usd
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CY2022Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	2751694000	usd
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CY2022Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	2751694000	usd
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CY2022Q4	us-gaap	Employee Stock Ownership Plan Esop Number Of Allocated Shares EmployeeStockOwnershipPlanESOPNumberOfAllocatedShares	1046850	shares
CY2023Q4	us-gaap	Employee Stock Ownership Plan Esop Number Of Committed To Be Released Shares EmployeeStockOwnershipPlanESOPNumberOfCommittedToBeReleasedShares	103230	shares
CY2022Q4	us-gaap	Employee Stock Ownership Plan Esop Number Of Committed To Be Released Shares EmployeeStockOwnershipPlanESOPNumberOfCommittedToBeReleasedShares	104464	shares
CY2023Q4	us-gaap	Employee Stock Ownership Plan Esop Number Of Suspense Shares EmployeeStockOwnershipPlanESOPNumberOfSuspenseShares	13270932	shares
CY2022Q4	us-gaap	Employee Stock Ownership Plan Esop Number Of Suspense Shares EmployeeStockOwnershipPlanESOPNumberOfSuspenseShares	13769628	shares
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CY2023Q4	us-gaap	Employee Stock Ownership Plan Esop Deferred Shares Fair Value EmployeeStockOwnershipPlanESOPDeferredSharesFairValue	188447000	usd
CY2022Q4	us-gaap	Employee Stock Ownership Plan Esop Deferred Shares Fair Value EmployeeStockOwnershipPlanESOPDeferredSharesFairValue	237526000	usd
CY2023Q4	us-gaap	Loss Contingency Accrual At Carrying Value LossContingencyAccrualAtCarryingValue	10800000	usd
CY2023Q4	us-gaap	Loss Contingency Accrual At Carrying Value LossContingencyAccrualAtCarryingValue	10800000	usd
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CY2023Q4	us-gaap	Derivative Assets DerivativeAssets	20456000	usd
CY2022Q4	us-gaap	Derivative Assets DerivativeAssets	23861000	usd
CY2023Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	63075000	usd
CY2022Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	81422000	usd
CY2023Q4	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	-24855000	usd
CY2022Q4	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	-69010000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	0	usd
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CY2021	us-gaap	Gain Loss On Foreign Currency Derivative Instruments Not Designated As Hedging Instruments GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments	5179000	usd
CY2023Q4	ebc	Credit Exposure To Interest Swap In Excess Of Termination Values CreditExposureToInterestSwapInExcessOfTerminationValues	400000	usd
CY2022Q4	ebc	Credit Exposure To Interest Swap In Excess Of Termination Values CreditExposureToInterestSwapInExcessOfTerminationValues	0	usd
CY2023	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	100000	usd
CY2022	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-200000	usd
CY2021	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-700000	usd
CY2023	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	76866000	usd
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	77299000	usd
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	69423000	usd
CY2023	us-gaap	Revenue Not From Contract With Customer Excluding Interest Income RevenueNotFromContractWithCustomerExcludingInterestIncome	-314619000	usd
CY2022	us-gaap	Revenue Not From Contract With Customer Excluding Interest Income RevenueNotFromContractWithCustomerExcludingInterestIncome	-549000	usd
CY2021	us-gaap	Revenue Not From Contract With Customer Excluding Interest Income RevenueNotFromContractWithCustomerExcludingInterestIncome	28014000	usd
CY2023	us-gaap	Noninterest Income NoninterestIncome	-237753000	usd
CY2022	us-gaap	Noninterest Income NoninterestIncome	76750000	usd
CY2021	us-gaap	Noninterest Income NoninterestIncome	97437000	usd
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CY2023	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	89860000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	314840000	usd
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CY2022	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-253278000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-866496000	usd
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CY2021	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-32983000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-110930000	usd
CY2023Q4	us-gaap	Deferred Gain Loss On Discontinuation Of Interest Rate Fair Value Hedge DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedge	41200000	usd
CY2022Q4	ebc	Deferred Gain Loss On Discontinuation Of Interest Rate Fair Value Hedge After Amortization DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedgeAfterAmortization	100000	usd
CY2021Q4	ebc	Deferred Gain Loss On Discontinuation Of Interest Rate Fair Value Hedge After Amortization DeferredGainLossOnDiscontinuationOfInterestRateFairValueHedgeAfterAmortization	7400000	usd
CY2021	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-88720000	usd
CY2021	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-22210000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-110930000	usd
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CY2022	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	3445000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-866496000	usd
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CY2023	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	280932000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	314840000	usd
CY2023	dei	Auditor Name AuditorName	Ernst & Young LLP
CY2023	dei	Auditor Location AuditorLocation	Boston, Massachusetts
CY2023	dei	Auditor Firm AuditorFirmId	42
CY2023Q4	ecd	Rule10b51 Arr Trmntd Flag Rule10b51ArrTrmntdFlag	false
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CY2023Q4	ecd	Non Rule10b51 Arr Trmntd Flag NonRule10b51ArrTrmntdFlag	false

Files In Submission

Name	View Source	Status
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$EBC
Eastern Bankshares, Inc. Stock $ebc

2024 Q1 Form 10-K Financial Statement

#000162828024006922 Filed on February 26, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$EBC Eastern Bankshares, Inc. Stock $ebc

2024 Q1 Form 10-K Financial Statement

#000162828024006922 Filed on February 26, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$EBC
Eastern Bankshares, Inc. Stock $ebc