$INDB
INDEPENDENT BANK CORP Stock $indb

$indb Overview Financials Valuation SEC Filings Company Website

2018 Q4 Form 10-K Financial Statement

#000077690120000064 Filed on February 27, 2020

Income Statement

Concept	2018 Q4	2018 Q3	2018 Q2
Revenue	$87.91M	$82.88M	$79.17M
YoY Change	20.63%	15.46%	16.19%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$3.900M	$4.100M	$3.800M
YoY Change	-7.14%	2.5%	-2.56%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$7.618M	$6.641M	$5.999M
YoY Change	51.03%	41.15%	37.03%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$38.20M	$42.98M	$40.37M
YoY Change	3.24%	17.66%	28.99%
Income Tax	$8.258M	$9.969M	$9.249M
% Of Pretax Income	21.62%	23.19%	22.91%
Net Earnings	$29.93M	$33.02M	$31.12M
YoY Change	35.67%	38.42%	51.33%
Net Earnings / Revenue	34.05%	39.84%	39.31%
Basic Earnings Per Share	$1.08	$1.20	$1.13
Diluted Earnings Per Share	$1.07	$1.20	$1.13
COMMON SHARES
Basic Shares Outstanding	27.82M shares	27.54M shares	27.53M shares
Diluted Shares Outstanding	27.87M shares	27.60M shares	27.58M shares

Balance Sheet

Concept	2018 Q4	2018 Q3	2018 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents
Short-Term Investments	$1.075B	$1.012B	$1.003B
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$97.58M	$95.94M	$95.84M
YoY Change	3.02%	1.09%	3.43%
Goodwill	$506.2M	$231.8M	$231.8M
YoY Change	97.66%	0.0%	0.0%
Intangibles	$15.25M
YoY Change	63.26%
Long-Term Investments
YoY Change
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$8.852B	$8.375B	$8.381B
YoY Change	9.52%	4.01%	4.54%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$141.0M	$142.0M
YoY Change	-100.0%	-21.67%	-10.69%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities		$141.0M	$142.0M
YoY Change		-21.67%	-10.69%
LONG-TERM LIABILITIES
Long-Term Debt	$110.9M	$108.0M	$108.0M
YoY Change	2.92%	0.0%	0.0%
Other Long-Term Liabilities	$92.00M	$101.0M	$90.00M
YoY Change	8.24%	3.06%	3.45%
Total Long-Term Liabilities	$110.9M	$209.0M	$198.0M
YoY Change	2.92%	1.46%	1.54%
TOTAL LIABILITIES
Total Short-Term Liabilities		$141.0M	$142.0M
Total Long-Term Liabilities	$110.9M	$209.0M	$198.0M
Total Liabilities	$7.778B	$7.377B	$7.404B
YoY Change	8.96%	3.59%	4.24%
SHAREHOLDERS EQUITY
Retained Earnings	$546.7M	$527.5M	$504.9M
YoY Change	17.34%	16.53%	15.39%
Common Stock	$279.0K	$274.0K	$274.0K
YoY Change	2.2%	0.37%	0.74%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$1.073B	$998.3M	$977.1M
YoY Change
Total Liabilities & Shareholders Equity	$8.852B	$8.375B	$8.381B
YoY Change	9.52%	4.01%	4.54%

Cashflow Statement

Concept	2018 Q4	2018 Q3	2018 Q2
OPERATING ACTIVITIES
Net Income	$29.93M	$33.02M	$31.12M
YoY Change	35.67%	38.42%	51.33%
Depreciation, Depletion And Amortization	$3.900M	$4.100M	$3.800M
YoY Change	-7.14%	2.5%	-2.56%
Cash From Operating Activities	$38.00M	$36.20M	$33.70M
YoY Change	-10.59%	-7.65%	185.59%
INVESTING ACTIVITIES
Capital Expenditures	-$3.000M	-$2.400M	-$2.900M
YoY Change	-53.85%	-45.45%	-66.67%
Acquisitions			$0.00
YoY Change
Other Investing Activities	-$124.4M	-$57.80M	-$127.6M
YoY Change	20.43%	402.61%	123.08%
Cash From Investing Activities	-$127.4M	-$60.20M	-$130.5M
YoY Change	16.03%	278.62%	98.03%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	89.00M	-48.30M	254.3M
YoY Change	319.81%	11975.0%	261.22%
NET CHANGE
Cash From Operating Activities	38.00M	36.20M	33.70M
Cash From Investing Activities	-127.4M	-60.20M	-130.5M
Cash From Financing Activities	89.00M	-48.30M	254.3M
Net Change In Cash	-400.0K	-72.30M	157.5M
YoY Change	-99.13%	-415.72%	866.26%
FREE CASH FLOW
Cash From Operating Activities	$38.00M	$36.20M	$33.70M
Capital Expenditures	-$3.000M	-$2.400M	-$2.900M
Free Cash Flow	$41.00M	$38.60M	$36.60M
YoY Change	-16.33%	-11.47%	78.54%

Facts In Submission

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CY2017	indb	Interchange And Atm Fees InterchangeAndAtmFees	17291000	USD
CY2019	us-gaap	Investment Banking Advisory Brokerage And Underwriting Fees And Commissions InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions	28719000	USD
CY2018	us-gaap	Investment Banking Advisory Brokerage And Underwriting Fees And Commissions InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions	26155000	USD
CY2017	us-gaap	Investment Banking Advisory Brokerage And Underwriting Fees And Commissions InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions	23802000	USD
CY2019	indb	Fees And Commission Mortgage Banking FeesAndCommissionMortgageBanking	11454000	USD
CY2018	indb	Fees And Commission Mortgage Banking FeesAndCommissionMortgageBanking	4071000	USD
CY2017	indb	Fees And Commission Mortgage Banking FeesAndCommissionMortgageBanking	4960000	USD
CY2019	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	5013000	USD
CY2018	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	4060000	USD
CY2017	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	4127000	USD
CY2019	indb	Gain Realized On Life Insurance Policies GainRealizedOnLifeInsurancePolicies	434000	USD
CY2018	indb	Gain Realized On Life Insurance Policies GainRealizedOnLifeInsurancePolicies	1463000	USD
CY2017	indb	Gain Realized On Life Insurance Policies GainRealizedOnLifeInsurancePolicies	0	USD
CY2019	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	6478000	USD
CY2018	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	2373000	USD
CY2017	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	3836000	USD
CY2019	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	21004000	USD
CY2018	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	13140000	USD
CY2017	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	11156000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	115294000	USD
CY2017	us-gaap	Noninterest Income NoninterestIncome	82994000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	155926000	USD
CY2019	us-gaap	Labor And Related Expense LaborAndRelatedExpense	149165000	USD
CY2018	us-gaap	Labor And Related Expense LaborAndRelatedExpense	124328000	USD
CY2017	us-gaap	Labor And Related Expense LaborAndRelatedExpense	116600000	USD
CY2019	us-gaap	Occupancy Net OccupancyNet	33207000	USD
CY2018	us-gaap	Occupancy Net OccupancyNet	27098000	USD
CY2017	us-gaap	Occupancy Net OccupancyNet	24693000	USD
CY2019	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	6516000	USD
CY2018	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	5125000	USD
CY2017	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	4988000	USD
CY2019	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	1394000	USD
CY2018	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	2774000	USD
CY2017	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	3068000	USD
CY2019	us-gaap	Advertising Expense AdvertisingExpense	5444000	USD
CY2018	us-gaap	Advertising Expense AdvertisingExpense	4942000	USD
CY2017	us-gaap	Advertising Expense AdvertisingExpense	4989000	USD
CY2019	us-gaap	Professional Fees ProfessionalFees	5448000	USD
CY2018	us-gaap	Professional Fees ProfessionalFees	3891000	USD
CY2017	us-gaap	Professional Fees ProfessionalFees	4038000	USD
CY2019	us-gaap	Cost Of Goods And Services Sold Amortization CostOfGoodsAndServicesSoldAmortization	5545000	USD
CY2018	us-gaap	Cost Of Goods And Services Sold Amortization CostOfGoodsAndServicesSoldAmortization	2344000	USD
CY2017	us-gaap	Cost Of Goods And Services Sold Amortization CostOfGoodsAndServicesSoldAmortization	2711000	USD
CY2019	indb	Debit Card Expense DebitCardExpense	4220000	USD
CY2018	indb	Debit Card Expense DebitCardExpense	3429000	USD
CY2017	indb	Debit Card Expense DebitCardExpense	3430000	USD
CY2019	indb	Availablefor Sale Securities Fixed Income Gross Realized Losses AvailableforSaleSecuritiesFixedIncomeGrossRealizedLosses	1462000	USD
CY2018	indb	Availablefor Sale Securities Fixed Income Gross Realized Losses AvailableforSaleSecuritiesFixedIncomeGrossRealizedLosses	0	USD
CY2017	indb	Availablefor Sale Securities Fixed Income Gross Realized Losses AvailableforSaleSecuritiesFixedIncomeGrossRealizedLosses	0	USD
CY2019	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	26433000	USD
CY2018	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	11168000	USD
CY2017	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	3393000	USD
CY2019	indb	Software Maintenance SoftwareMaintenance	5511000	USD
CY2018	indb	Software Maintenance SoftwareMaintenance	4202000	USD
CY2017	indb	Software Maintenance SoftwareMaintenance	3636000	USD
CY2019	us-gaap	Other Noninterest Expense OtherNoninterestExpense	39976000	USD
CY2018	us-gaap	Other Noninterest Expense OtherNoninterestExpense	36668000	USD
CY2017	us-gaap	Other Noninterest Expense OtherNoninterestExpense	32813000	USD
CY2019	us-gaap	Noninterest Expense NoninterestExpense	284321000	USD
CY2018	us-gaap	Noninterest Expense NoninterestExpense	225969000	USD
CY2017	us-gaap	Noninterest Expense NoninterestExpense	204359000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	218108000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	134545000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	52933000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	34304000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	47341000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	165175000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	121622000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	87204000	USD
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.03
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.41
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.19
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	5.03
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.40
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.19
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	32810433	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	27592380	shares
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	27294028	shares
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	45801	shares
CY2018	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	61428	shares
CY2017	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	78076	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	32856234	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	27653808	shares
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	27372104	shares
CY2019	us-gaap	Net Income Loss NetIncomeLoss	165175000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	121622000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	87204000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	10345000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-4501000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-677000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	10331000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	4829000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	443000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	1334000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-1558000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	260000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	19342000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	1886000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-494000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	184517000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	123508000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	86710000	USD
CY2016Q4	us-gaap	Stockholders Equity StockholdersEquity	864690000	USD
CY2017Q4	us-gaap	New Accounting Pronouncement Or Change In Accounting Principle Cumulative Effect Of Change On Equity Or Net Assets1 NewAccountingPronouncementOrChangeInAccountingPrincipleCumulativeEffectOfChangeOnEquityOrNetAssets1	177000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	87204000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-494000	USD
CY2017	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	34997000	USD
CY2017	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	23468000	USD
CY2017	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	214000	USD
CY2017	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3333000	USD
CY2017	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-1422000	USD
CY2017	us-gaap	Stock Issued During Period Value Other StockIssuedDuringPeriodValueOther	1636000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	943809000	USD
CY2018	us-gaap	Prior Period Reclassification Adjustment PriorPeriodReclassificationAdjustment	0	USD
CY2018Q3	us-gaap	New Accounting Pronouncement Or Change In Accounting Principle Cumulative Effect Of Change On Equity Or Net Assets1 NewAccountingPronouncementOrChangeInAccountingPrincipleCumulativeEffectOfChangeOnEquityOrNetAssets1	0	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	121622000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	1886000	USD
CY2018	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	42051000	USD
CY2018	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	42474000	USD
CY2018	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	184000	USD
CY2018	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	4225000	USD
CY2018	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-1371000	USD
CY2018	us-gaap	Stock Issued During Period Value Other StockIssuedDuringPeriodValueOther	2712000	USD
CY2018	us-gaap	Increase Decrease In Deferred Compensation IncreaseDecreaseInDeferredCompensation	0	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	1073490000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	165175000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	19342000	USD
CY2019	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	57729000	USD
CY2019	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	499693000	USD
CY2019	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	281000	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	4403000	USD
CY2019	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-1463000	USD
CY2019	us-gaap	Stock Issued During Period Value Other StockIssuedDuringPeriodValueOther	4951000	USD
CY2019	us-gaap	Increase Decrease In Deferred Compensation IncreaseDecreaseInDeferredCompensation	0	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	1708143000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	165175000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	121622000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	87204000	USD
CY2019	us-gaap	Depreciation And Amortization DepreciationAndAmortization	19439000	USD
CY2018	us-gaap	Depreciation And Amortization DepreciationAndAmortization	15629000	USD
CY2017	us-gaap	Depreciation And Amortization DepreciationAndAmortization	15760000	USD
CY2019	indb	Change In Unamortized Net Loan Costs And Premiums ChangeInUnamortizedNetLoanCostsAndPremiums	10086000	USD
CY2018	indb	Change In Unamortized Net Loan Costs And Premiums ChangeInUnamortizedNetLoanCostsAndPremiums	-365000	USD
CY2017	indb	Change In Unamortized Net Loan Costs And Premiums ChangeInUnamortizedNetLoanCostsAndPremiums	79000	USD
CY2019	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	6000000	USD
CY2018	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	4775000	USD
CY2017	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	2950000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	10594000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-4497000	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	9211000	USD
CY2019	indb	Tax Expenserelatedtoachangeintaxlaw TaxExpenserelatedtoachangeintaxlaw	0	USD
CY2018	indb	Tax Expenserelatedtoachangeintaxlaw TaxExpenserelatedtoachangeintaxlaw	0	USD
CY2017	indb	Tax Expenserelatedtoachangeintaxlaw TaxExpenserelatedtoachangeintaxlaw	466000	USD
CY2019	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	1566000	USD
CY2018	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	-1225000	USD
CY2019	us-gaap	Gain Loss On Investments GainLossOnInvestments	-1462000	USD
CY2017	us-gaap	Gain Loss On Investments GainLossOnInvestments	3000	USD
CY2019	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	474000	USD
CY2018	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	1126000	USD
CY2017	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	108000	USD
CY2019	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-401000	USD
CY2018	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-112000	USD
CY2017	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-288000	USD
CY2019	us-gaap	Sale Leaseback Transaction Current Period Gain Recognized SaleLeasebackTransactionCurrentPeriodGainRecognized	578000	USD
CY2018	us-gaap	Sale Leaseback Transaction Current Period Gain Recognized SaleLeasebackTransactionCurrentPeriodGainRecognized	730000	USD
CY2017	us-gaap	Sale Leaseback Transaction Current Period Gain Recognized SaleLeasebackTransactionCurrentPeriodGainRecognized	1034000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	4403000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	4225000	USD
CY2017	us-gaap	Share Based Compensation ShareBasedCompensation	3333000	USD
CY2019	us-gaap	Life Insurance Corporate Or Bank Owned Change In Value LifeInsuranceCorporateOrBankOwnedChangeInValue	5013000	USD
CY2018	us-gaap	Life Insurance Corporate Or Bank Owned Change In Value LifeInsuranceCorporateOrBankOwnedChangeInValue	4060000	USD
CY2017	us-gaap	Life Insurance Corporate Or Bank Owned Change In Value LifeInsuranceCorporateOrBankOwnedChangeInValue	4127000	USD
CY2019	indb	Gain Realized On Life Insurance Policies GainRealizedOnLifeInsurancePolicies	434000	USD
CY2018	indb	Gain Realized On Life Insurance Policies GainRealizedOnLifeInsurancePolicies	1463000	USD
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	10669000	USD
CY2018	us-gaap	Operating Lease Payments OperatingLeasePayments	0	USD
CY2017	us-gaap	Operating Lease Payments OperatingLeasePayments	0	USD
CY2019	indb	Change In Fair Value On Loans Held For Sale ChangeInFairValueOnLoansHeldForSale	822000	USD
CY2018	indb	Change In Fair Value On Loans Held For Sale ChangeInFairValueOnLoansHeldForSale	-51000	USD
CY2017	indb	Change In Fair Value On Loans Held For Sale ChangeInFairValueOnLoansHeldForSale	-113000	USD
CY2019	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	675000	USD
CY2018	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	180000	USD
CY2017	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	520000	USD
CY2018	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	0	USD
CY2017	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	0	USD
CY2019	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	-59932000	USD
CY2018	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	1714000	USD
CY2017	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	-1258000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	39850000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-503000	USD
CY2017	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-20022000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	19283000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	7100000	USD
CY2017	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-3825000	USD
CY2019	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	51347000	USD
CY2018	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	20215000	USD
CY2017	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	43705000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	216522000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	141837000	USD
CY2017	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	130909000	USD
CY2019	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	1461000	USD
CY2018	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	5752000	USD
CY2017	us-gaap	Proceeds From Sale Of Available For Sale Securities Equity ProceedsFromSaleOfAvailableForSaleSecuritiesEquity	0	USD
CY2019	us-gaap	Increase Decrease In Equity Securities Fv Ni IncreaseDecreaseInEquitySecuritiesFvNi	711000	USD
CY2018	us-gaap	Increase Decrease In Equity Securities Fv Ni IncreaseDecreaseInEquitySecuritiesFvNi	6315000	USD
CY2017	us-gaap	Increase Decrease In Equity Securities Fv Ni IncreaseDecreaseInEquitySecuritiesFvNi	0	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	45863000	USD
CY2017	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	1027000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	51104000	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	82418000	USD
CY2017	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	54191000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	68677000	USD
CY2018	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	78990000	USD
CY2017	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	140885000	USD
CY2019	us-gaap	Proceeds From Maturities Repayments And Calls Of Trading Securities Heldforinvestment ProceedsFromMaturitiesRepaymentsAndCallsOfTradingSecuritiesHeldforinvestment	126991000	USD
CY2018	us-gaap	Proceeds From Maturities Repayments And Calls Of Trading Securities Heldforinvestment ProceedsFromMaturitiesRepaymentsAndCallsOfTradingSecuritiesHeldforinvestment	82355000	USD
CY2017	us-gaap	Proceeds From Maturities Repayments And Calls Of Trading Securities Heldforinvestment ProceedsFromMaturitiesRepaymentsAndCallsOfTradingSecuritiesHeldforinvestment	78757000	USD
CY2019	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	59967000	USD
CY2018	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	195538000	USD
CY2017	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	89033000	USD
CY2019	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	-18896000	USD
CY2018	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	2376000	USD
CY2017	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	-386000	USD
CY2019	indb	Investmentin Low Income Housing Projects InvestmentinLowIncomeHousingProjects	-10052000	USD
CY2018	indb	Investmentin Low Income Housing Projects InvestmentinLowIncomeHousingProjects	-3434000	USD
CY2017	indb	Investmentin Low Income Housing Projects InvestmentinLowIncomeHousingProjects	-7645000	USD
CY2019	us-gaap	Payments To Acquire Life Insurance Policies PaymentsToAcquireLifeInsurancePolicies	163000	USD
CY2018	us-gaap	Payments To Acquire Life Insurance Policies PaymentsToAcquireLifeInsurancePolicies	164000	USD
CY2017	us-gaap	Payments To Acquire Life Insurance Policies PaymentsToAcquireLifeInsurancePolicies	164000	USD
CY2019	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	3162000	USD
CY2018	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	2850000	USD
CY2017	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	0	USD
CY2019	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-27816000	USD
CY2018	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	258633000	USD
CY2017	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	204702000	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	105264000	USD
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	6906000	USD
CY2017	us-gaap	Cash Acquired In Excess Of Payments To Acquire Business CashAcquiredInExcessOfPaymentsToAcquireBusiness	6289000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	16583000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	11106000	USD
CY2017	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	25080000	USD
CY2019	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	3796000	USD
CY2018	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	2189000	USD
CY2017	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	6306000	USD
CY2019	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	2488000	USD
CY2018	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	387000	USD
CY2017	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	3784000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	20160000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-387511000	USD
CY2017	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-316769000	USD
CY2019	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	-45272000	USD
CY2018	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	-1430000	USD
CY2017	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	-19509000	USD
CY2019	us-gaap	Increase Decrease In Other Deposits IncreaseDecreaseInOtherDeposits	-160637000	USD
CY2018	us-gaap	Increase Decrease In Other Deposits IncreaseDecreaseInOtherDeposits	280017000	USD
CY2017	us-gaap	Increase Decrease In Other Deposits IncreaseDecreaseInOtherDeposits	177241000	USD
CY2019	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	-132046000	USD
CY2018	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	67046000	USD
CY2019	indb	Increase Decrease In Federal Home Loan Bank Advances Long Term IncreaseDecreaseInFederalHomeLoanBankAdvancesLongTerm	-25000000	USD
CY2018	indb	Increase Decrease In Federal Home Loan Bank Advances Long Term IncreaseDecreaseInFederalHomeLoanBankAdvancesLongTerm	-2475000	USD
CY2017	indb	Increase Decrease In Federal Home Loan Bank Advances Long Term IncreaseDecreaseInFederalHomeLoanBankAdvancesLongTerm	0	USD
CY2018	indb	Increase Decreasein Customer Repurchase Agreements IncreaseDecreaseinCustomerRepurchaseAgreements	-21503000	USD
CY2017	indb	Increase Decreasein Customer Repurchase Agreements IncreaseDecreaseinCustomerRepurchaseAgreements	-14234000	USD
CY2019	us-gaap	Proceeds From Lines Of Credit ProceedsFromLinesOfCredit	49980000	USD
CY2018	us-gaap	Proceeds From Lines Of Credit ProceedsFromLinesOfCredit	0	USD
CY2017	us-gaap	Proceeds From Lines Of Credit ProceedsFromLinesOfCredit	0	USD
CY2019	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	49980000	USD
CY2019	us-gaap	Proceeds From Debt Net Of Issuance Costs ProceedsFromDebtNetOfIssuanceCosts	74867000	USD
CY2018	us-gaap	Proceeds From Debt Net Of Issuance Costs ProceedsFromDebtNetOfIssuanceCosts	0	USD
CY2017	us-gaap	Proceeds From Debt Net Of Issuance Costs ProceedsFromDebtNetOfIssuanceCosts	0	USD
CY2019	indb	Repayments Of Junior Subordinated Debt RepaymentsOfJuniorSubordinatedDebt	13329000	USD
CY2018	indb	Repayments Of Junior Subordinated Debt RepaymentsOfJuniorSubordinatedDebt	0	USD
CY2017	indb	Repayments Of Junior Subordinated Debt RepaymentsOfJuniorSubordinatedDebt	0	USD
CY2019	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	49526000	USD
CY2018	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	0	USD
CY2017	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	0	USD
CY2019	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	34767000	USD
CY2018	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	USD
CY2017	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	USD
CY2019	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	281000	USD
CY2018	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	184000	USD
CY2017	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	214000	USD
CY2019	us-gaap	Proceeds From Repurchase Of Equity ProceedsFromRepurchaseOfEquity	-1463000	USD
CY2018	us-gaap	Proceeds From Repurchase Of Equity ProceedsFromRepurchaseOfEquity	-1371000	USD
CY2017	us-gaap	Proceeds From Repurchase Of Equity ProceedsFromRepurchaseOfEquity	-1422000	USD
CY2019	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	4951000	USD
CY2018	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	2712000	USD
CY2017	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	1636000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	53274000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	40167000	USD
CY2017	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	34045000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-336163000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	283013000	USD
CY2017	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	109881000	USD
CY2019	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-99481000	USD
CY2018	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	37339000	USD
CY2017	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-75979000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	250455000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	213116000	USD
CY2016Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	289095000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	150974000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	250455000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	213116000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	49704000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	25337000	USD
CY2017	us-gaap	Interest Paid Net InterestPaidNet	18626000	USD
CY2019	us-gaap	Income Taxes Paid IncomeTaxesPaid	39575000	USD
CY2018	us-gaap	Income Taxes Paid IncomeTaxesPaid	27809000	USD
CY2017	us-gaap	Income Taxes Paid IncomeTaxesPaid	32865000	USD
CY2017	us-gaap	Transfer Of Other Real Estate TransferOfOtherRealEstate	511000	USD
CY2019	indb	Capitalcommitmentrelatingto Low Income Housing Projectinvestmentsnoncash CapitalcommitmentrelatingtoLowIncomeHousingProjectinvestmentsnoncash	36543000	USD
CY2018	indb	Capitalcommitmentrelatingto Low Income Housing Projectinvestmentsnoncash CapitalcommitmentrelatingtoLowIncomeHousingProjectinvestmentsnoncash	2833000	USD
CY2017	indb	Capitalcommitmentrelatingto Low Income Housing Projectinvestmentsnoncash CapitalcommitmentrelatingtoLowIncomeHousingProjectinvestmentsnoncash	20000	USD
CY2019	indb	Transferofcustomerrepurchaseagreementstodepositsnoncash Transferofcustomerrepurchaseagreementstodepositsnoncash	0	USD
CY2018	indb	Transferofcustomerrepurchaseagreementstodepositsnoncash Transferofcustomerrepurchaseagreementstodepositsnoncash	141176000	USD
CY2017	indb	Transferofcustomerrepurchaseagreementstodepositsnoncash Transferofcustomerrepurchaseagreementstodepositsnoncash	0	USD
CY2019Q1	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	32777000	USD
CY2018	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	0	USD
CY2017	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	0	USD
CY2019	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	14951000	USD
CY2018	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	0	USD
CY2017	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	0	USD
CY2019	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	499693000	USD
CY2018	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	42474000	USD
CY2017	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	23468000	USD
CY2019Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets	2711067000	USD
CY2018Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets	362286000	USD
CY2017Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets	179252000	USD
CY2019Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Liabilities BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities	2106110000	USD
CY2018Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Liabilities BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities	312906000	USD
CY2017Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Liabilities BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities	162073000	USD
CY2019Q1	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	32800000	USD
CY2019Q1	us-gaap	Operating Lease Liability OperatingLeaseLiability	34100000	USD
CY2018Q4	us-gaap	Deferred Rent Credit DeferredRentCredit	1300000	USD
CY2019	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	<div style="line-height:120%;padding-top:18px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Reclassification</span></div><div style="line-height:120%;padding-top:6px;text-align:justify;text-indent:36px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Certain previously reported amounts have been reclassified to conform to the current year’s presentation.</span></div>
CY2019	us-gaap	Use Of Estimates UseOfEstimates	<div style="line-height:120%;padding-top:18px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Use of Estimates</span></div><div style="line-height:120%;padding-top:6px;text-align:justify;text-indent:36px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could vary from these estimates. Material estimates that are particularly susceptible to significant changes in the near-term relate to the determination of the allowance for loan losses, income taxes, valuation and potential impairment of investment securities, other-than-temporary impairment ("OTTI") of certain investment securities, as well as valuation of goodwill and other intangibles and their respective analyses of impairment.</span></div>
CY2019	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<div style="line-height:120%;padding-top:18px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Significant Concentrations of Credit Risk</span></div><div style="line-height:120%;padding-top:6px;text-align:justify;text-indent:36px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The vast majority of the Bank’s lending activities are conducted in Massachusetts and Rhode Island. The Bank originates commercial and industrial loans, commercial and residential real estate loans, including construction loans, small business loans, home equity loans, and other consumer loans for its portfolio. The Bank considers a concentration of credit to a particular industry to exist when the aggregate credit exposure which includes direct, indirect or contingent obligations to a borrower, an affiliated group of borrowers or a nonaffiliated group of borrowers engaged in one industry, exceeds 10% of the Bank’s loan portfolio.</span></div><div style="line-height:120%;padding-top:12px;text-align:justify;text-indent:36px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Loans originated by the Bank to lessors of nonresidential buildings represented </span><span style="font-family:inherit;font-size:10pt;"><span>17.5%</span></span><span style="font-family:inherit;font-size:10pt;"> and </span><span style="font-family:inherit;font-size:10pt;">15.1%</span><span style="font-family:inherit;font-size:10pt;"> of the total loan portfolio at </span><span style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">December 31, 2019</span><span style="font-family:inherit;font-size:10pt;"> and </span><span style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">2018</span><span style="font-family:inherit;font-size:10pt;">, respectively. Within this concentration category, the Company believes it is well diversified among collateral property types and tenant industries.</span></div>
CY2019Q4	us-gaap	Loans And Leases Receivable Impaired Commitment To Lend LoansAndLeasesReceivableImpairedCommitmentToLend	2100000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Impaired Commitment To Lend LoansAndLeasesReceivableImpairedCommitmentToLend	1300000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	64293000	USD
CY2019Q2	us-gaap	Business Combination Acquired Receivables Fair Value BusinessCombinationAcquiredReceivablesFairValue	23200000	USD
CY2019Q4	us-gaap	Trading Securities Debt TradingSecuritiesDebt	2200000	USD
CY2018Q4	us-gaap	Trading Securities Debt TradingSecuritiesDebt	1500000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	21300000	USD
CY2018Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	19500000	USD
CY2019	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	1566000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	63214000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	1079000	USD
CY2018Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	6838339000	USD
CY2018Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	59060000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	6906194000	USD
CY2016Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	61566000	USD
CY2017	us-gaap	Allowance For Loan And Lease Losses Write Offs AllowanceForLoanAndLeaseLossesWriteOffs	6209000	USD
CY2017	us-gaap	Allowance For Loan And Lease Loss Recovery Of Bad Debts AllowanceForLoanAndLeaseLossRecoveryOfBadDebts	2336000	USD
CY2018	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	-1225000	USD
CY2019	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	18000	USD
CY2018	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	874000	USD
CY2019	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	1548000	USD
CY2018	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-2099000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	420703000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	6118000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	397000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	426424000	USD
CY2018Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	450548000	USD
CY2018Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	1233000	USD
CY2018Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	9029000	USD
CY2018Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	442752000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Amortized Cost Before Other Than Temporary Impairment HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment	740806000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	13428000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	971000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	753263000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Amortized Cost Before Other Than Temporary Impairment HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment	611490000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	2533000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	10383000	USD
CY2018Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	603640000	USD
CY2019Q4	indb	Available For Sale Securities And Held To Maturity Securities Amortized Cost AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesAmortizedCost	1161509000	USD
CY2019Q4	indb	Available For Sale Securities And Held To Maturity Securities Gross Unrealized Gains AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesGrossUnrealizedGains	19546000	USD
CY2019Q4	indb	Available For Sale Securities And Held To Maturity Securities Gross Unrealized Losses AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesGrossUnrealizedLosses	1368000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale And Held To Maturity DebtSecuritiesAvailableForSaleAndHeldToMaturity	1179687000	USD
CY2018Q4	indb	Available For Sale Securities And Held To Maturity Securities Amortized Cost AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesAmortizedCost	1062038000	USD
CY2018Q4	indb	Available For Sale Securities And Held To Maturity Securities Gross Unrealized Gains AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesGrossUnrealizedGains	3766000	USD
CY2018Q4	indb	Available For Sale Securities And Held To Maturity Securities Gross Unrealized Losses AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesGrossUnrealizedLosses	19412000	USD
CY2018Q4	us-gaap	Debt Securities Available For Sale And Held To Maturity DebtSecuritiesAvailableForSaleAndHeldToMaturity	1046392000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	420703000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Amortized Cost Before Other Than Temporary Impairment HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment	740806000	USD
CY2019Q4	indb	Available For Saleand Held To Maturity Debt Securities Maturities Within One Year Amortized Cost AvailableForSaleandHeldToMaturityDebtSecuritiesMaturitiesWithinOneYearAmortizedCost	14962000	USD
CY2019Q4	indb	Available For Saleand Held To Maturity Debt Securities Maturities Within One Year Fair Value AvailableForSaleandHeldToMaturityDebtSecuritiesMaturitiesWithinOneYearFairValue	14992000	USD
CY2019Q4	indb	Available For Saleand Held To Maturity Debt Securities Maturities After One Through Five Years Amortized Cost AvailableForSaleandHeldToMaturityDebtSecuritiesMaturitiesAfterOneThroughFiveYearsAmortizedCost	104891000	USD
CY2019Q4	indb	Available For Saleand Held To Maturity Debt Securities Maturities After One Through Five Years Fair Value AvailableForSaleandHeldToMaturityDebtSecuritiesMaturitiesAfterOneThroughFiveYearsFairValue	105531000	USD
CY2019Q4	indb	Available For Saleand Held To Maturity Debt Securities Maturities After Five Through Ten Years Amortized Cost AvailableForSaleandHeldToMaturityDebtSecuritiesMaturitiesAfterFiveThroughTenYearsAmortizedCost	104614000	USD
CY2019Q4	indb	Available For Saleand Held To Maturity Debt Securities Maturities After Five Through Ten Years Fair Value AvailableForSaleandHeldToMaturityDebtSecuritiesMaturitiesAfterFiveThroughTenYearsFairValue	106983000	USD
CY2019Q4	indb	Available For Saleand Held To Maturity Debt Securities Maturities After Ten Years Amortized Cost AvailableForSaleandHeldToMaturityDebtSecuritiesMaturitiesAfterTenYearsAmortizedCost	937042000	USD
CY2019Q4	indb	Available For Saleand Held To Maturity Debt Securities Maturities After Ten Years Fair Value AvailableForSaleandHeldToMaturityDebtSecuritiesMaturitiesAfterTenYearsFairValue	952181000	USD
CY2019Q4	indb	Available For Saleand Held To Maturity Debt Securities Amortized Cost AvailableForSaleandHeldToMaturityDebtSecuritiesAmortizedCost	1161509000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale And Held To Maturity DebtSecuritiesAvailableForSaleAndHeldToMaturity	1179687000	USD
CY2019Q4	indb	Callable Securities In Investment Portfolio CallableSecuritiesInInvestmentPortfolio	17400000	USD
CY2019Q4	us-gaap	Pledged Financial Instruments Not Separately Reported Securities Pledged PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesPledged	375500000	USD
CY2018Q4	us-gaap	Pledged Financial Instruments Not Separately Reported Securities Pledged PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesPledged	361100000	USD
CY2019Q4	indb	Investmentsinobligationsofindividualstatescountiesormunicipalitieswhichexceed10ofequity Investmentsinobligationsofindividualstatescountiesormunicipalitieswhichexceed10ofequity	0	USD
CY2019Q4	indb	Available For Sale And Held To Maturity Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions	32	holding
CY2019Q4	indb	Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	89834000	USD
CY2019Q4	indb	Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months	329000	USD
CY2019Q4	indb	Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	40229000	USD
CY2019Q4	indb	Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months	1039000	USD
CY2019Q4	indb	Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position Fair Value AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	130063000	USD
CY2019Q4	indb	Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position Aggregate Loss AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss	1368000	USD
CY2018Q4	indb	Available For Sale And Held To Maturity Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions	205	holding
CY2018Q4	indb	Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	202901000	USD
CY2018Q4	indb	Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months	2486000	USD
CY2018Q4	indb	Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	566107000	USD
CY2018Q4	indb	Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months	16926000	USD
CY2018Q4	indb	Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position Fair Value AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	769008000	USD
CY2018Q4	indb	Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position Aggregate Loss AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss	19412000	USD
CY2019	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Period Increase Decrease OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsPeriodIncreaseDecrease	0	USD
CY2019Q4	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld	0	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	64293000	USD
CY2019	us-gaap	Allowance For Loan And Lease Losses Write Offs AllowanceForLoanAndLeaseLossesWriteOffs	5205000	USD
CY2019	us-gaap	Allowance For Loan And Lease Loss Recovery Of Bad Debts AllowanceForLoanAndLeaseLossRecoveryOfBadDebts	2652000	USD
CY2019	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	6000000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	67740000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	66760000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	980000	USD
CY2019Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	8809155000	USD
CY2019Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	49628000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	8873639000	USD
CY2017Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	60643000	USD
CY2018	us-gaap	Allowance For Loan And Lease Losses Write Offs AllowanceForLoanAndLeaseLossesWriteOffs	2597000	USD
CY2018	us-gaap	Allowance For Loan And Lease Loss Recovery Of Bad Debts AllowanceForLoanAndLeaseLossRecoveryOfBadDebts	1472000	USD
CY2018	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	4775000	USD
CY2017	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	2950000	USD
CY2017Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	60643000	USD
CY2017Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	59301000	USD
CY2017Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	1342000	USD
CY2017Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	6269729000	USD
CY2017Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	72801000	USD
CY2017Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	6355553000	USD
CY2019Q4	indb	Unamortized Loan Commitmentand Originationfees UnamortizedLoanCommitmentandOriginationfees	7100000	USD
CY2017Q4	indb	Unamortized Loan Commitmentand Originationfees UnamortizedLoanCommitmentandOriginationfees	6100000	USD
CY2019Q4	indb	Unamortized Discountsor Premiums UnamortizedDiscountsorPremiums	21600000	USD
CY2018Q4	indb	Unamortized Discountsor Premiums UnamortizedDiscountsorPremiums	15200000	USD
CY2017Q4	indb	Unamortized Discountsor Premiums UnamortizedDiscountsorPremiums	9400000	USD
CY2019Q4	indb	Significant Advanced Considered For Risk Rating Change SignificantAdvancedConsideredForRiskRatingChange	50000	USD
CY2019Q4	us-gaap	Notes Receivable Net NotesReceivableNet	6119185000	USD
CY2018Q4	us-gaap	Notes Receivable Net NotesReceivableNet	4874718000	USD
CY2019Q4	indb	Days To Be Termed As Non Accrual Loans DaysToBeTermedAsNonAccrualLoans	P90D
CY2019Q4	indb	Days To Be Termed As Non Accrual Loans DaysToBeTermedAsNonAccrualLoans	P90D
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	45892000	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	45413000	USD
CY2019Q4	indb	Tdrs Recorded Investment On Nonaccrual Status TdrsRecordedInvestmentOnNonaccrualStatus	24800000	USD
CY2018Q4	indb	Tdrs Recorded Investment On Nonaccrual Status TdrsRecordedInvestmentOnNonaccrualStatus	29300000	USD
CY2019Q4	indb	Foreclosedresidentialrealestatepropertyheldbythecreditor Foreclosedresidentialrealestatepropertyheldbythecreditor	0	USD
CY2018Q4	indb	Foreclosedresidentialrealestatepropertyheldbythecreditor Foreclosedresidentialrealestatepropertyheldbythecreditor	0	USD
CY2019Q4	us-gaap	Mortgage Loans In Process Of Foreclosure Amount MortgageLoansInProcessOfForeclosureAmount	3294000	USD
CY2018Q4	us-gaap	Mortgage Loans In Process Of Foreclosure Amount MortgageLoansInProcessOfForeclosureAmount	3174000	USD
CY2019Q4	indb	Number Of Financing Receivables Thirty To Fifty Nine Days Past Due NumberOfFinancingReceivablesThirtyToFiftyNineDaysPastDue	447	loan
CY2019Q4	indb	Number Of Financing Receivables Sixty To Eighty Nine Days Past Due NumberOfFinancingReceivablesSixtyToEightyNineDaysPastDue	43	loan
CY2019Q4	indb	Number Of Financing Receivables Equal To Greater Than Ninety Days NumberOfFinancingReceivablesEqualToGreaterThanNinetyDays	113	loan
CY2019Q4	indb	Number Of Financing Receivables Total Past Due NumberOfFinancingReceivablesTotalPastDue	603	loan
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	25485000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	8848154000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	8873639000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	2157000	USD
CY2018Q4	indb	Number Of Financing Receivables Thirty To Fifty Nine Days Past Due NumberOfFinancingReceivablesThirtyToFiftyNineDaysPastDue	400	loan
CY2018Q4	indb	Number Of Financing Receivables Sixty To Eighty Nine Days Past Due NumberOfFinancingReceivablesSixtyToEightyNineDaysPastDue	56	loan
CY2018Q4	indb	Number Of Financing Receivables Equal To Greater Than Ninety Days NumberOfFinancingReceivablesEqualToGreaterThanNinetyDays	110	loan
CY2018Q4	indb	Number Of Financing Receivables Total Past Due NumberOfFinancingReceivablesTotalPastDue	566	loan
CY2018Q4	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	46348000	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	6859846000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	6906194000	USD
CY2018Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	5000	USD
CY2019Q4	indb	Tdrs Recorded Investment On Accrual Status TdrsRecordedInvestmentOnAccrualStatus	19599000	USD
CY2018Q4	indb	Tdrs Recorded Investment On Accrual Status TdrsRecordedInvestmentOnAccrualStatus	23849000	USD
CY2019Q4	indb	Tdrs Recorded Investment On Nonaccrual Status TdrsRecordedInvestmentOnNonaccrualStatus	24766000	USD
CY2018Q4	indb	Tdrs Recorded Investment On Nonaccrual Status TdrsRecordedInvestmentOnNonaccrualStatus	29348000	USD
CY2019Q4	indb	Financing Receivable Recorded Investment Trouble Debt Restructuring FinancingReceivableRecordedInvestmentTroubleDebtRestructuring	44365000	USD
CY2018Q4	indb	Financing Receivable Recorded Investment Trouble Debt Restructuring FinancingReceivableRecordedInvestmentTroubleDebtRestructuring	53197000	USD
CY2019Q4	indb	Amount Of Specific Reserves Included In Allowance For Loan Losses Associated With Trouble Debt Restructuring AmountOfSpecificReservesIncludedInAllowanceForLoanLossesAssociatedWithTroubleDebtRestructuring	855000	USD
CY2018Q4	indb	Amount Of Specific Reserves Included In Allowance For Loan Losses Associated With Trouble Debt Restructuring AmountOfSpecificReservesIncludedInAllowanceForLoanLossesAssociatedWithTroubleDebtRestructuring	1079000	USD
CY2019Q4	indb	Additional Commitments To Lend To Borrower For Trouble Debt Restructuring AdditionalCommitmentsToLendToBorrowerForTroubleDebtRestructuring	63000	USD
CY2018Q4	indb	Additional Commitments To Lend To Borrower For Trouble Debt Restructuring AdditionalCommitmentsToLendToBorrowerForTroubleDebtRestructuring	982000	USD
CY2019	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	13	contract
CY2019	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	2189000	USD
CY2019	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	2231000	USD
CY2018	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	29	contract
CY2018	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	38898000	USD
CY2018	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	42457000	USD
CY2017	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	54	contract
CY2017	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	8130000	USD
CY2017	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	8175000	USD
CY2019	indb	Financing Receivable Modifications Post Modification Recorded Investment Extended Maturity FinancingReceivableModificationsPostModificationRecordedInvestmentExtendedMaturity	1565000	USD
CY2018	indb	Financing Receivable Modifications Post Modification Recorded Investment Extended Maturity FinancingReceivableModificationsPostModificationRecordedInvestmentExtendedMaturity	2878000	USD
CY2017	indb	Financing Receivable Modifications Post Modification Recorded Investment Extended Maturity FinancingReceivableModificationsPostModificationRecordedInvestmentExtendedMaturity	5881000	USD
CY2019	indb	Financing Receivable Modifications Post Modification Recorded Investment Adjusted Interest Rate FinancingReceivableModificationsPostModificationRecordedInvestmentAdjustedInterestRate	150000	USD
CY2018	indb	Financing Receivable Modifications Post Modification Recorded Investment Adjusted Interest Rate FinancingReceivableModificationsPostModificationRecordedInvestmentAdjustedInterestRate	57000	USD
CY2019	indb	Financing Receivable Modifications Post Modification Recorded Investment Combination Of Rate And Maturity FinancingReceivableModificationsPostModificationRecordedInvestmentCombinationOfRateAndMaturity	441000	USD
CY2018	indb	Financing Receivable Modifications Post Modification Recorded Investment Combination Of Rate And Maturity FinancingReceivableModificationsPostModificationRecordedInvestmentCombinationOfRateAndMaturity	38812000	USD
CY2017	indb	Financing Receivable Modifications Post Modification Recorded Investment Combination Of Rate And Maturity FinancingReceivableModificationsPostModificationRecordedInvestmentCombinationOfRateAndMaturity	568000	USD
CY2019	indb	Financing Receivable Modifications Post Modification Recorded Investment Court Ordered Concession FinancingReceivableModificationsPostModificationRecordedInvestmentCourtOrderedConcession	75000	USD
CY2018	indb	Financing Receivable Modifications Post Modification Recorded Investment Court Ordered Concession FinancingReceivableModificationsPostModificationRecordedInvestmentCourtOrderedConcession	710000	USD
CY2017	indb	Financing Receivable Modifications Post Modification Recorded Investment Court Ordered Concession FinancingReceivableModificationsPostModificationRecordedInvestmentCourtOrderedConcession	1726000	USD
CY2019	indb	Financing Receivable Modifications Post Modification Recorded Investments FinancingReceivableModificationsPostModificationRecordedInvestments	2231000	USD
CY2018	indb	Financing Receivable Modifications Post Modification Recorded Investments FinancingReceivableModificationsPostModificationRecordedInvestments	42457000	USD
CY2017	indb	Financing Receivable Modifications Post Modification Recorded Investments FinancingReceivableModificationsPostModificationRecordedInvestments	8175000	USD
CY2019	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	contract
CY2017	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	1	contract
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	980000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	49628000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	68140000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	980000	USD
CY2019	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	59682000	USD
CY2019	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	1537000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	1079000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	59060000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	68514000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	1079000	USD
CY2018	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	63522000	USD
CY2018	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	1554000	USD
CY2017Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	1342000	USD
CY2017Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	72801000	USD
CY2017Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	79276000	USD
CY2017Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	1342000	USD
CY2017	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	76180000	USD
CY2017	us-gaap	Impaired Financing Receivable Interest Income Cash Basis Method ImpairedFinancingReceivableInterestIncomeCashBasisMethod	2026000	USD
CY2019Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Outstanding Balance CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesOutstandingBalance	18358000	USD
CY2018Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Outstanding Balance CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesOutstandingBalance	9749000	USD
CY2018Q4	us-gaap	Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYield	1191000	USD
CY2017Q4	us-gaap	Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYield	1791000	USD
CY2019	us-gaap	Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield Additions CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldAdditions	1464000	USD
CY2018	us-gaap	Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield Additions CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldAdditions	0	USD
CY2019	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	1751000	USD
CY2018	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	1135000	USD
CY2019	indb	Certainloansacquiredinatransfernotaccountedforasdebtsecuritiesaccretableyieldadjustmentchangesinexpectedcashflow Certainloansacquiredinatransfernotaccountedforasdebtsecuritiesaccretableyieldadjustmentchangesinexpectedcashflow	803000	USD
CY2018	indb	Certainloansacquiredinatransfernotaccountedforasdebtsecuritiesaccretableyieldadjustmentchangesinexpectedcashflow Certainloansacquiredinatransfernotaccountedforasdebtsecuritiesaccretableyieldadjustmentchangesinexpectedcashflow	310000	USD
CY2019	us-gaap	Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield Reclassifications From Nonaccretable Difference CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldReclassificationsFromNonaccretableDifference	227000	USD
CY2018	us-gaap	Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield Reclassifications From Nonaccretable Difference CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldReclassificationsFromNonaccretableDifference	225000	USD
CY2019Q4	us-gaap	Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYield	1934000	USD
CY2018Q4	us-gaap	Certain Loans Acquired In Transfer Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYield	1191000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	218921000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	182787000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	95247000	USD
CY2018Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	85206000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	123674000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	97581000	USD
CY2019	us-gaap	Depreciation Depreciation	11400000	USD
CY2018	us-gaap	Depreciation Depreciation	9100000	USD
CY2017	us-gaap	Depreciation Depreciation	8500000	USD
CY2019	us-gaap	Rental Income Nonoperating RentalIncomeNonoperating	1600000	USD
CY2017	us-gaap	Rental Income Nonoperating RentalIncomeNonoperating	1300000	USD
CY2019	us-gaap	Operating Leases Income Statement Depreciation Expense On Property Subject To Or Held For Lease OperatingLeasesIncomeStatementDepreciationExpenseOnPropertySubjectToOrHeldForLease	1300000	USD
CY2017	us-gaap	Operating Leases Income Statement Depreciation Expense On Property Subject To Or Held For Lease OperatingLeasesIncomeStatementDepreciationExpenseOnPropertySubjectToOrHeldForLease	939000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	506206000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	256105000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	29286000	USD
CY2018Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	15250000	USD
CY2019Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	535492000	USD
CY2018Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	271355000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	256105000	USD
CY2017Q4	us-gaap	Goodwill Goodwill	231806000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	250101000	USD
CY2018	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	24299000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	506206000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	256105000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	48583000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	19297000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	29286000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	37240000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	21990000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	15250000	USD
CY2019Q4	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6800000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2700000	USD
CY2017	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	3500000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	6179000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	5315000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	4539000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	3948000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	3162000	USD
CY2019Q4	us-gaap	Acquired Finite Lived Intangible Assets Weighted Average Useful Life AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife	P9Y9M18D
CY2019Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	1097407000	USD
CY2019Q4	indb	Time Deposit Maturities Next Twelve Months Percent Of Total TimeDepositMaturitiesNextTwelveMonthsPercentOfTotal	0.786
CY2018Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	511292000	USD
CY2018Q4	indb	Time Deposit Maturities Next Twelve Months Percent Of Total TimeDepositMaturitiesNextTwelveMonthsPercentOfTotal	0.719
CY2019Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	204690000	USD
CY2019Q4	indb	Time Deposit Maturities Year Two Percent Of Total TimeDepositMaturitiesYearTwoPercentOfTotal	0.147
CY2018Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	111487000	USD
CY2018Q4	indb	Time Deposit Maturities Year Two Percent Of Total TimeDepositMaturitiesYearTwoPercentOfTotal	0.157
CY2019Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	55615000	USD
CY2019Q4	indb	Time Deposit Maturities Year Three Percent Of Total TimeDepositMaturitiesYearThreePercentOfTotal	0.040
CY2018Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	41523000	USD
CY2018Q4	indb	Time Deposit Maturities Year Three Percent Of Total TimeDepositMaturitiesYearThreePercentOfTotal	0.058
CY2019Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	24038000	USD
CY2019Q4	indb	Time Deposit Maturities Year Four Percent Of Total TimeDepositMaturitiesYearFourPercentOfTotal	0.017
CY2018Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	27040000	USD
CY2018Q4	indb	Time Deposit Maturities Year Four Percent Of Total TimeDepositMaturitiesYearFourPercentOfTotal	0.038
CY2019Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	13565000	USD
CY2019Q4	indb	Time Deposit Maturities Year Five Percent Of Total TimeDepositMaturitiesYearFivePercentOfTotal	0.010
CY2018Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	19761000	USD
CY2018Q4	indb	Time Deposit Maturities Year Five Percent Of Total TimeDepositMaturitiesYearFivePercentOfTotal	0.028
CY2019Q4	us-gaap	Time Deposits TimeDeposits	1395315000	USD
CY2019Q4	indb	Time Deposits Percent Of Total TimeDepositsPercentOfTotal	1.000
CY2018Q4	us-gaap	Time Deposits TimeDeposits	711103000	USD
CY2018Q4	indb	Time Deposits Percent Of Total TimeDepositsPercentOfTotal	1.000
CY2019Q4	us-gaap	Deposit Liabilities Reclassified As Loans Receivable1 DepositLiabilitiesReclassifiedAsLoansReceivable1	5000000.0	USD
CY2018Q4	us-gaap	Deposit Liabilities Reclassified As Loans Receivable1 DepositLiabilitiesReclassifiedAsLoansReceivable1	3300000	USD
CY2019Q4	us-gaap	Deposit Liabilities Collateral Issued Financial Instruments DepositLiabilitiesCollateralIssuedFinancialInstruments	323100000	USD
CY2018Q4	us-gaap	Deposit Liabilities Collateral Issued Financial Instruments DepositLiabilitiesCollateralIssuedFinancialInstruments	356800000	USD
CY2019Q4	indb	Certificatesof Depositsover250000.00 CertificatesofDepositsover250000.00	244700000	USD
CY2018Q4	indb	Certificatesof Depositsover250000.00 CertificatesofDepositsover250000.00	104900000	USD
CY2018Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	147046000	USD
CY2018Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Average Interest Rate Of Amounts Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateOfAmountsDueWithinOneYearOfBalanceSheetDate	0.0268
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	104976000	USD
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Average Interest Rate Of Amounts Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateOfAmountsDueWithinOneYearOfBalanceSheetDate	0.0179
CY2018Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due From One To Two Years Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromOneToTwoYearsOfBalanceSheetDate	0	USD
CY2018Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Average Interest Rate One To Two Years From Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateOneToTwoYearsFromBalanceSheetDate	0
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due From One To Two Years Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromOneToTwoYearsOfBalanceSheetDate	10042000	USD
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Average Interest Rate One To Two Years From Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateOneToTwoYearsFromBalanceSheetDate	0.0295
CY2018Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due From Two To Three Years Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromTwoToThreeYearsOfBalanceSheetDate	0	USD
CY2018Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Average Interest Rate Two To Three Years From Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateTwoToThreeYearsFromBalanceSheetDate	0
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Branch Of Fhlb Bank Amount Of Advances By Branch FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch	115018000	USD
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Weighted Average Interest Rate FederalHomeLoanBankAdvancesWeightedAverageInterestRate	0.0189
CY2018Q4	us-gaap	Federal Home Loan Bank Advances Branch Of Fhlb Bank Amount Of Advances By Branch FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch	147046000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	0	USD
CY2018Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	35000000.0	USD
CY2018Q4	us-gaap	Federal Home Loan Bank Advances Weighted Average Interest Rate FederalHomeLoanBankAdvancesWeightedAverageInterestRate	0.0268
CY2019Q4	us-gaap	Debt Instrument Unamortized Premium DebtInstrumentUnamortizedPremium	730000	USD
CY2018Q4	us-gaap	Debt Instrument Unamortized Premium DebtInstrumentUnamortizedPremium	760000	USD
CY2019Q4	indb	Total Federal Home Loan Bank Advances TotalFederalHomeLoanBankAdvances	115748000	USD
CY2018Q4	indb	Total Federal Home Loan Bank Advances TotalFederalHomeLoanBankAdvances	147806000	USD
CY2019Q4	indb	Federal Home Loan Bank Advances Weighted Average Interest Rateinclusiveof Swaps FederalHomeLoanBankAdvancesWeightedAverageInterestRateinclusiveofSwaps	0.0188
CY2018Q4	indb	Federal Home Loan Bank Advances Weighted Average Interest Rateinclusiveof Swaps FederalHomeLoanBankAdvancesWeightedAverageInterestRateinclusiveofSwaps	0.0255
CY2019Q4	us-gaap	Loans Pledged As Collateral LoansPledgedAsCollateral	2500000000	USD
CY2018Q4	us-gaap	Loans Pledged As Collateral LoansPledgedAsCollateral	1600000000	USD
CY2019Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	0	USD
CY2018Q4	indb	Customer Repurchase Agreementsandothershorttermborrowings CustomerRepurchaseAgreementsandothershorttermborrowings	162700000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	50000000.0	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	50000000.0	USD
CY2019	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	104000	USD
CY2018	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	248000	USD
CY2017	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	257000	USD
CY2019Q4	us-gaap	Long Term Debt LongTermDebt	74906000	USD
CY2018Q4	us-gaap	Long Term Debt LongTermDebt	0	USD
CY2019Q4	us-gaap	Subordinated Debt SubordinatedDebt	49601000	USD
CY2018Q4	us-gaap	Subordinated Debt SubordinatedDebt	34728000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	187355000	USD
CY2018Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	110901000	USD
CY2019	us-gaap	Interest Expense Long Term Debt InterestExpenseLongTermDebt	8200000	USD
CY2018	us-gaap	Interest Expense Long Term Debt InterestExpenseLongTermDebt	4200000	USD
CY2017	us-gaap	Interest Expense Long Term Debt InterestExpenseLongTermDebt	3900000	USD
CY2018Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	35000000.0	USD
CY2018Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	35000000.0	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	0	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	75000000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	0	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	0	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	112888000	USD
CY2019Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	187888000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	165175000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	121622000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	87204000	USD
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	32810433	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	27592380	shares
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	27294028	shares
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	45801	shares
CY2018	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	61428	shares
CY2017	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	78076	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	32856234	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	27653808	shares
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	27372104	shares
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.03
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.41
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.19
CY2019	indb	Effect Of Dilutive Shares EffectOfDilutiveShares	0
CY2018	indb	Effect Of Dilutive Shares EffectOfDilutiveShares	-0.01
CY2017	indb	Effect Of Dilutive Shares EffectOfDilutiveShares	0
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	5.03
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.40
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.19
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	4403000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	4225000	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3333000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	1238000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	1188000	USD
CY2017	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	1362000	USD
CY2019Q4	indb	Share Based Compensation Arrangement By Share Based Payment Award Options Price Per Share Common Stock Average High And Low Price Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsPricePerShareCommonStockAverageHighAndLowPriceIntrinsicValue	83.64
CY2019	us-gaap	Maximum Length Of Time Hedged In Interest Rate Cash Flow Hedge1 MaximumLengthOfTimeHedgedInInterestRateCashFlowHedge1	P4Y10M24D
CY2018	indb	Amortization Of Deferred Hedge Gains Losses AmortizationOfDeferredHedgeGainsLosses	231000	USD
CY2017	indb	Amortization Of Deferred Hedge Gains Losses AmortizationOfDeferredHedgeGainsLosses	244000	USD
CY2019Q4	us-gaap	Fair Value Hedges At Fair Value Net FairValueHedgesAtFairValueNet	0	USD
CY2019	indb	Change In Fair Value On Loans Held For Sale ChangeInFairValueOnLoansHeldForSale	822000	USD
CY2018	indb	Change In Fair Value On Loans Held For Sale ChangeInFairValueOnLoansHeldForSale	-51000	USD
CY2017	indb	Change In Fair Value On Loans Held For Sale ChangeInFairValueOnLoansHeldForSale	-113000	USD
CY2019	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	13200000	USD
CY2018	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	3600000	USD
CY2017	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	4700000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	2346000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	1000000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	-441000	USD
CY2019Q4	us-gaap	Derivative Net Liability Position Aggregate Fair Value DerivativeNetLiabilityPositionAggregateFairValue	26000000.0	USD
CY2018Q4	us-gaap	Derivative Net Liability Position Aggregate Fair Value DerivativeNetLiabilityPositionAggregateFairValue	176000	USD
CY2019Q4	indb	Exposureto Institutional Counterparties ExposuretoInstitutionalCounterparties	25400000	USD
CY2018Q4	indb	Exposureto Institutional Counterparties ExposuretoInstitutionalCounterparties	18400000	USD
CY2019Q4	indb	Exposure To Counterparties Relating To Customer Related Positions ExposureToCounterpartiesRelatingToCustomerRelatedPositions	51000000.0	USD
CY2018Q4	indb	Exposure To Counterparties Relating To Customer Related Positions ExposureToCounterpartiesRelatingToCustomerRelatedPositions	6400000	USD
CY2019Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	76705000	USD
CY2019Q4	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	0	USD
CY2019Q4	us-gaap	Derivative Assets DerivativeAssets	76705000	USD
CY2019Q4	us-gaap	Derivative Collateral Obligation To Return Securities DerivativeCollateralObligationToReturnSecurities	24882000	USD
CY2019Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	0	USD
CY2019Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral	51823000	USD
CY2019Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	53715000	USD
CY2019Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	0	USD
CY2019Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	53715000	USD
CY2019Q4	us-gaap	Derivative Collateral Right To Reclaim Securities DerivativeCollateralRightToReclaimSecurities	24882000	USD
CY2019Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	25493000	USD
CY2019Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral	3340000	USD
CY2018Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	26113000	USD
CY2018Q4	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	0	USD
CY2018Q4	us-gaap	Derivative Assets DerivativeAssets	26113000	USD
CY2018Q4	us-gaap	Derivative Collateral Obligation To Return Securities DerivativeCollateralObligationToReturnSecurities	6556000	USD
CY2018Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	8528000	USD
CY2018Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral	11029000	USD
CY2018Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	17523000	USD
CY2018Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	0	USD
CY2018Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	17523000	USD
CY2018Q4	us-gaap	Derivative Collateral Right To Reclaim Securities DerivativeCollateralRightToReclaimSecurities	6556000	USD
CY2018Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	173000	USD
CY2018Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral	10794000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	27980000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	25129000	USD
CY2017	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	28852000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	14359000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	13672000	USD
CY2017	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	9278000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	42339000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	38801000	USD
CY2017	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	38130000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	9080000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-3080000	USD
CY2017	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	7953000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1514000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-1417000	USD
CY2017	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1258000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	10594000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-4497000	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	9211000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	52933000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	34304000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	47341000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	45803000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.2100
CY2018	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	32744000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.2100
CY2017	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	47091000	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.3500
CY2019	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	12262000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.0563
CY2018	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	9633000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.0618
CY2017	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	6817000	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.0507
CY2019	us-gaap	Income Tax Reconciliation Nondeductible Expense Other IncomeTaxReconciliationNondeductibleExpenseOther	582000	USD
CY2019	indb	Effective Income Tax Rate Reconciliation Merger And Other Related Costs EffectiveIncomeTaxRateReconciliationMergerAndOtherRelatedCosts	0.0027
CY2018	us-gaap	Income Tax Reconciliation Nondeductible Expense Other IncomeTaxReconciliationNondeductibleExpenseOther	130000	USD
CY2018	indb	Effective Income Tax Rate Reconciliation Merger And Other Related Costs EffectiveIncomeTaxRateReconciliationMergerAndOtherRelatedCosts	0.0008
CY2017	us-gaap	Income Tax Reconciliation Nondeductible Expense Other IncomeTaxReconciliationNondeductibleExpenseOther	213000	USD
CY2017	indb	Effective Income Tax Rate Reconciliation Merger And Other Related Costs EffectiveIncomeTaxRateReconciliationMergerAndOtherRelatedCosts	0.0016
CY2019	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	17000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.0001
CY2018	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	49000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.0003
CY2017	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	31000	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.0002
CY2019	indb	Effective Income Tax Rate Reconciliation Revaluationof Net Deferred Tax Assets EffectiveIncomeTaxRateReconciliationRevaluationofNetDeferredTaxAssets	0	USD
CY2019	indb	Effective Income Tax Rate Reconciliation Revaluationof Net Deferred Tax Asset Percent EffectiveIncomeTaxRateReconciliationRevaluationofNetDeferredTaxAssetPercent	0
CY2018	indb	Effective Income Tax Rate Reconciliation Revaluationof Net Deferred Tax Assets EffectiveIncomeTaxRateReconciliationRevaluationofNetDeferredTaxAssets	0	USD
CY2018	indb	Effective Income Tax Rate Reconciliation Revaluationof Net Deferred Tax Asset Percent EffectiveIncomeTaxRateReconciliationRevaluationofNetDeferredTaxAssetPercent	0
CY2017	indb	Effective Income Tax Rate Reconciliation Revaluationof Net Deferred Tax Assets EffectiveIncomeTaxRateReconciliationRevaluationofNetDeferredTaxAssets	1895000	USD
CY2017	indb	Effective Income Tax Rate Reconciliation Revaluationof Net Deferred Tax Asset Percent EffectiveIncomeTaxRateReconciliationRevaluationofNetDeferredTaxAssetPercent	0.0141
CY2019	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	2675000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.0123
CY2018	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	3960000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.0254
CY2017	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	3960000	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.0294
CY2019	indb	Effective Income Tax Rate Reconciliation Increasein Cash Surrender Valueof Life Insurance Amount EffectiveIncomeTaxRateReconciliationIncreaseinCashSurrenderValueofLifeInsuranceAmount	1144000	USD
CY2019	indb	Effective Income Tax Rate Reconciliation Increasein Cash Surrender Valueof Life Insurance Percent EffectiveIncomeTaxRateReconciliationIncreaseinCashSurrenderValueofLifeInsurancePercent	0.0052
CY2018	indb	Effective Income Tax Rate Reconciliation Increasein Cash Surrender Valueof Life Insurance Amount EffectiveIncomeTaxRateReconciliationIncreaseinCashSurrenderValueofLifeInsuranceAmount	1160000	USD
CY2018	indb	Effective Income Tax Rate Reconciliation Increasein Cash Surrender Valueof Life Insurance Percent EffectiveIncomeTaxRateReconciliationIncreaseinCashSurrenderValueofLifeInsurancePercent	0.0074
CY2017	indb	Effective Income Tax Rate Reconciliation Increasein Cash Surrender Valueof Life Insurance Amount EffectiveIncomeTaxRateReconciliationIncreaseinCashSurrenderValueofLifeInsuranceAmount	1445000	USD
CY2017	indb	Effective Income Tax Rate Reconciliation Increasein Cash Surrender Valueof Life Insurance Percent EffectiveIncomeTaxRateReconciliationIncreaseinCashSurrenderValueofLifeInsurancePercent	0.0107
CY2019	us-gaap	Income Tax Reconciliation Tax Credits Investment IncomeTaxReconciliationTaxCreditsInvestment	1696000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Investment EffectiveIncomeTaxRateReconciliationTaxCreditsInvestment	0.0078
CY2018	us-gaap	Income Tax Reconciliation Tax Credits Investment IncomeTaxReconciliationTaxCreditsInvestment	1030000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Investment EffectiveIncomeTaxRateReconciliationTaxCreditsInvestment	0.0066
CY2017	us-gaap	Income Tax Reconciliation Tax Credits Investment IncomeTaxReconciliationTaxCreditsInvestment	1253000	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Investment EffectiveIncomeTaxRateReconciliationTaxCreditsInvestment	0.0093
CY2019	indb	Effective Income Tax Rate Reconciliation Stock Based Compensation Amount EffectiveIncomeTaxRateReconciliationStockBasedCompensationAmount	824000	USD
CY2019	indb	Effective Income Tax Rate Reconciliation Stock Based Compensation Percent EffectiveIncomeTaxRateReconciliationStockBasedCompensationPercent	0.0038
CY2018	indb	Effective Income Tax Rate Reconciliation Stock Based Compensation Amount EffectiveIncomeTaxRateReconciliationStockBasedCompensationAmount	885000	USD
CY2018	indb	Effective Income Tax Rate Reconciliation Stock Based Compensation Percent EffectiveIncomeTaxRateReconciliationStockBasedCompensationPercent	0.0057
CY2017	indb	Effective Income Tax Rate Reconciliation Stock Based Compensation Amount EffectiveIncomeTaxRateReconciliationStockBasedCompensationAmount	1258000	USD
CY2017	indb	Effective Income Tax Rate Reconciliation Stock Based Compensation Percent EffectiveIncomeTaxRateReconciliationStockBasedCompensationPercent	0.0094
CY2019	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	757000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.0035
CY2018	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	566000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.0036
CY2017	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	987000	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.0073
CY2019	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	1365000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	0.0063
CY2018	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	-651000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	-0.0042
CY2017	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	197000	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	0.0015
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	52933000	USD
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.2428
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	34304000	USD
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.2200
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	47341000	USD
CY2017	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.3520
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	13855000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	11922000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	18993000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	17764000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	1708000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	1636000	USD
CY2019Q4	indb	Deferred Tax Asset Loan Fair Value Adjustment DeferredTaxAssetLoanFairValueAdjustment	6804000	USD
CY2018Q4	indb	Deferred Tax Asset Loan Fair Value Adjustment DeferredTaxAssetLoanFairValueAdjustment	4761000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	2546000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	170000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	0	USD
CY2018Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	1850000	USD
CY2019Q4	indb	Deferred Tax Asset Operating Lease Liability DeferredTaxAssetOperatingLeaseLiability	16393000	USD
CY2018Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	0	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	1311000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	1561000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	61610000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	39664000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	187000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	170000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	61423000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	39494000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	5802000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	3803000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Deferred Financing Costs DeferredTaxLiabilitiesDeferredExpenseDeferredFinancingCosts	4944000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Deferred Financing Costs DeferredTaxLiabilitiesDeferredExpenseDeferredFinancingCosts	4759000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Derivatives DeferredTaxLiabilitiesDerivatives	6461000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Derivatives DeferredTaxLiabilitiesDerivatives	2413000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	8194000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	5259000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Goodwill DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill	10645000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Goodwill DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill	10388000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	3487000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	3483000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	15911000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	0	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	3965000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	1139000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	59409000	USD
CY2018Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	31244000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	2014000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	8250000	USD
CY2019Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	11200000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	142000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	73000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	215000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	127000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	444000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	532000	USD
CY2019	indb	Unrecognized Tax Benefits Increase Resultingfrom Current Period Tax Positionsfederalbenefitofstatetaxamount UnrecognizedTaxBenefitsIncreaseResultingfromCurrentPeriodTaxPositionsfederalbenefitofstatetaxamount	116000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	-10000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	24000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	18000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	43000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	53000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	29000	USD
CY2019Q4	indb	Original Investmentin Low Income Housing Projects OriginalInvestmentinLowIncomeHousingProjects	96275000	USD
CY2018Q4	indb	Original Investmentin Low Income Housing Projects OriginalInvestmentinLowIncomeHousingProjects	50232000	USD
CY2017Q4	indb	Original Investmentin Low Income Housing Projects OriginalInvestmentinLowIncomeHousingProjects	47399000	USD
CY2019Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	72510000	USD
CY2018Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	33681000	USD
CY2017Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	35225000	USD
CY2019Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	34967000	USD
CY2018Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	3935000	USD
CY2017Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	4536000	USD
CY2019	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	7342000	USD
CY2018	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	5407000	USD
CY2017	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	5654000	USD
CY2019	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	5645000	USD
CY2018	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	4377000	USD
CY2017	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	4402000	USD
CY2019	us-gaap	Income Loss From Affordable Housing Projects Equity Method Investments IncomeLossFromAffordableHousingProjectsEquityMethodInvestments	1696000	USD
CY2018	us-gaap	Income Loss From Affordable Housing Projects Equity Method Investments IncomeLossFromAffordableHousingProjectsEquityMethodInvestments	1030000	USD
CY2017	us-gaap	Income Loss From Affordable Housing Projects Equity Method Investments IncomeLossFromAffordableHousingProjectsEquityMethodInvestments	1253000	USD
CY2019	indb	Multiemployer Plans Period Contributions Significance Of Contributions Percentage MultiemployerPlansPeriodContributionsSignificanceOfContributionsPercentage	0.05
CY2019Q4	indb	Defined Benefit Plan Fair Valueof Plan Assets Excluding Net Asset Value Investments DefinedBenefitPlanFairValueofPlanAssetsExcludingNetAssetValueInvestments	5726000	USD
CY2019Q4	indb	Defined Benefit Plan Alternative Investments Fair Value Of Plan Assets DefinedBenefitPlanAlternativeInvestmentsFairValueOfPlanAssets	5927000	USD
CY2019	us-gaap	Pension Expense PensionExpense	1400000	USD
CY2018	us-gaap	Pension Expense PensionExpense	1100000	USD
CY2017	us-gaap	Pension Expense PensionExpense	1900000	USD
CY2019	indb	Defined Benefit Plan Requisite Age DefinedBenefitPlanRequisiteAge	65	age
CY2019	indb	Defined Benefit Plan Requisite Service Period DefinedBenefitPlanRequisiteServicePeriod	P10Y
CY2019	indb	Defined Benefit Plan Death Benefit DefinedBenefitPlanDeathBenefit	5000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	18300000	USD
CY2018Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	16600000	USD
CY2019	indb	Incentive Plans And Discretionary Bonus Expense IncentivePlansAndDiscretionaryBonusExpense	16300000	USD
CY2018	indb	Incentive Plans And Discretionary Bonus Expense IncentivePlansAndDiscretionaryBonusExpense	13800000	USD
CY2017	indb	Incentive Plans And Discretionary Bonus Expense IncentivePlansAndDiscretionaryBonusExpense	10900000	USD
CY2019	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent DefinedContributionPlanEmployerMatchingContributionPercent	0.25
CY2019	us-gaap	Defined Contribution Plan Maximum Annual Contributions Per Employee Percent DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent	0.06
CY2019	indb	Defined Contribution Plan Nondiscretionary Requisite Service Period DefinedContributionPlanNondiscretionaryRequisiteServicePeriod	P1Y
CY2019	indb	Defined Contribution Plan Nondiscretionary Requisiteservicehours DefinedContributionPlanNondiscretionaryRequisiteservicehours	1,000
CY2019	indb	Defined Contribution Plan Employer Safe Harbor Contribution Amount DefinedContributionPlanEmployerSafeHarborContributionAmount	0.03
CY2019	indb	Defined Contribution Plan Employer Discretionary Contribution Percentageupto Social Security Limit DefinedContributionPlanEmployerDiscretionaryContributionPercentageuptoSocialSecurityLimit	0.02
CY2019	indb	Defined Contribution Plan Nondiscretionary Employer Contribution Percent Over Social Security Limit DefinedContributionPlanNondiscretionaryEmployerContributionPercentOverSocialSecurityLimit	0.05
CY2019	us-gaap	Deferred Compensation Arrangement With Individual Contributions By Employer DeferredCompensationArrangementWithIndividualContributionsByEmployer	142000	USD
CY2018	us-gaap	Deferred Compensation Arrangement With Individual Contributions By Employer DeferredCompensationArrangementWithIndividualContributionsByEmployer	142000	USD
CY2017	us-gaap	Deferred Compensation Arrangement With Individual Contributions By Employer DeferredCompensationArrangementWithIndividualContributionsByEmployer	143000	USD
CY2019Q4	us-gaap	Long Term Debt LongTermDebt	74906000	USD
CY2019Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	72219000	USD
CY2019	indb	Othernoninterestincome Asc606 OthernoninterestincomeASC606	8696000	USD
CY2018	indb	Othernoninterestincome Asc606 OthernoninterestincomeASC606	4432000	USD
CY2017	indb	Othernoninterestincome Asc606 OthernoninterestincomeASC606	4569000	USD
CY2019	indb	Totalnoninterestincomeinscopeof Asc606 TotalnoninterestincomeinscopeofASC606	80116000	USD
CY2018	indb	Totalnoninterestincomeinscopeof Asc606 TotalnoninterestincomeinscopeofASC606	68709000	USD
CY2017	indb	Totalnoninterestincomeinscopeof Asc606 TotalnoninterestincomeinscopeofASC606	64259000	USD
CY2019	indb	Totalnoninterestincomeoutofscopeof Asc606 TotalnoninterestincomeoutofscopeofASC606	35178000	USD
CY2018	indb	Totalnoninterestincomeoutofscopeof Asc606 TotalnoninterestincomeoutofscopeofASC606	19796000	USD
CY2017	indb	Totalnoninterestincomeoutofscopeof Asc606 TotalnoninterestincomeoutofscopeofASC606	18735000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	115294000	USD
CY2018	us-gaap	Noninterest Income NoninterestIncome	88505000	USD
CY2017	us-gaap	Noninterest Income NoninterestIncome	82994000	USD
CY2019Q4	indb	Investment Management Income Receivable InvestmentManagementIncomeReceivable	2341000	USD
CY2018Q4	indb	Investment Management Income Receivable InvestmentManagementIncomeReceivable	1893000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	12055000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	2761000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	9294000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-1462000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-411000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-1051000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentBeforeTaxPortionAttributableToParent	13517000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	3172000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	10345000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	16725000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	4708000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	12017000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	2346000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	660000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	1686000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	14379000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	4048000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	10331000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	-2123000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-597000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-1526000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax	8000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	2000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	6000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Before Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax	276000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	78000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	198000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	1855000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	521000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	1334000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	26041000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	6699000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	19342000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-5923000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-1422000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-4501000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentBeforeTaxPortionAttributableToParent	-5923000	USD
CY2018	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	-1422000	USD
CY2018	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-4501000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	7717000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	2169000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	5548000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	1000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	281000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	719000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	6717000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	1888000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	4829000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	1521000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	428000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	1093000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax	-372000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-105000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-267000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Before Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax	276000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	78000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	198000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	-2169000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	-611000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-1558000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	2963000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	1077000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	1886000	USD
CY2017	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-996000	USD
CY2017	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-321000	USD
CY2017	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-675000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	3000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	1000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	2000	USD
CY2017	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentBeforeTaxPortionAttributableToParent	-999000	USD
CY2017	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	-322000	USD
CY2017	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-677000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	307000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	125000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	182000	USD
CY2017	indb	Other Comprehensive Income Loss Reclassification Adjustmentfrom Aoc Ion Borrowings Expensebefore Tax OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIonBorrowingsExpensebeforeTax	-441000	USD
CY2017	indb	Other Comprehensive Income Loss Reclassification Adjustmentfrom Aoc Ion Borrowings Expense Tax OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIonBorrowingsExpenseTax	-180000	USD
CY2017	indb	Other Comprehensive Income Loss Reclassification Adjustmentfrom Aoc Ion Borrowings Expense Netof Tax OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIonBorrowingsExpenseNetofTax	-261000	USD
CY2017	us-gaap	Other Comprehensive Income Derivatives Qualifying As Hedges Before Tax Portion Attributable To Parent OtherComprehensiveIncomeDerivativesQualifyingAsHedgesBeforeTaxPortionAttributableToParent	748000	USD
CY2017	us-gaap	Other Comprehensive Income Derivatives Qualifying As Hedges Tax Portion Attributable To Parent OtherComprehensiveIncomeDerivativesQualifyingAsHedgesTaxPortionAttributableToParent	305000	USD
CY2017	us-gaap	Other Comprehensive Income Derivatives Qualifying As Hedges Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent	443000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	-995000	USD
CY2017	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-407000	USD
CY2017	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-588000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax	-278000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-113000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-165000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Before Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax	276000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	113000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	163000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	441000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	181000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	260000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-692000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-198000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-494000	USD
CY2009Q4	indb	Deferred Gain Loss On Cash Flow Hedge DeferredGainLossOnCashFlowHedge	1400000	USD
CY2017Q4	indb	Deferred Gain Loss On Cash Flow Hedge DeferredGainLossOnCashFlowHedge	137000	USD
CY2016Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1337000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-494000	USD
CY2017Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1831000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	1886000	USD
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1173000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	19342000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	18169000	USD
CY2019Q4	us-gaap	Property Subject To Or Available For Operating Lease Number Of Units PropertySubjectToOrAvailableForOperatingLeaseNumberOfUnits	94
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	56600000	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	10718000	USD
CY2019	us-gaap	Short Term Lease Cost ShortTermLeaseCost	116000	USD
CY2019	us-gaap	Variable Lease Cost VariableLeaseCost	0	USD
CY2019	us-gaap	Lease Cost LeaseCost	10834000	USD
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P6Y5M4D
CY2019Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0275
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	11752000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	11052000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	7121000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	10438000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	8528000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	14900000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	63791000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	5489000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	58302000	USD
CY2019Q4	us-gaap	Cash Reserve Deposit Required And Made CashReserveDepositRequiredAndMade	0	USD
CY2018Q4	us-gaap	Cash Reserve Deposit Required And Made CashReserveDepositRequiredAndMade	53500000	USD
CY2019	us-gaap	Cash Dividends Paid To Parent Company By Consolidated Subsidiaries CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries	181700000	USD
CY2018	us-gaap	Cash Dividends Paid To Parent Company By Consolidated Subsidiaries CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries	71200000	USD
CY2019Q4	indb	Redemptionof Trust Preferred Securities RedemptionofTrustPreferredSecurities	13000000.0	USD
CY2019Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	91543000	USD
CY2018Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	73749000	USD
CY2019Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	122144000	USD
CY2018Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	79167000	USD
CY2019Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	119624000	USD
CY2018Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	82875000	USD
CY2019Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	113703000	USD
CY2018Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	87910000	USD
CY2019Q1	us-gaap	Interest Expense InterestExpense	9018000	USD
CY2018Q1	us-gaap	Interest Expense InterestExpense	5278000	USD
CY2019Q2	us-gaap	Interest Expense InterestExpense	16125000	USD
CY2018Q2	us-gaap	Interest Expense InterestExpense	5999000	USD
CY2019Q3	us-gaap	Interest Expense InterestExpense	15026000	USD
CY2018Q3	us-gaap	Interest Expense InterestExpense	6641000	USD
CY2019Q4	us-gaap	Interest Expense InterestExpense	13710000	USD
CY2018Q4	us-gaap	Interest Expense InterestExpense	7618000	USD
CY2019Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	82525000	USD
CY2018Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	68471000	USD
CY2019Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	106019000	USD
CY2018Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	73168000	USD
CY2019Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	104598000	USD
CY2018Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	76234000	USD
CY2019Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	99993000	USD
CY2018Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	80292000	USD
CY2019Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1000000	USD
CY2018Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	500000	USD
CY2019Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1000000	USD
CY2018Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	2000000	USD
CY2019Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	0	USD
CY2018Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1075000	USD
CY2019Q4	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	4000000	USD
CY2018Q4	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1200000	USD
CY2019Q1	us-gaap	Noninterest Income NoninterestIncome	21533000	USD
CY2018Q1	us-gaap	Noninterest Income NoninterestIncome	19863000	USD
CY2019Q2	us-gaap	Noninterest Income NoninterestIncome	28648000	USD
CY2018Q2	us-gaap	Noninterest Income NoninterestIncome	21887000	USD
CY2019Q3	us-gaap	Noninterest Income NoninterestIncome	31816000	USD
CY2018Q3	us-gaap	Noninterest Income NoninterestIncome	23264000	USD
CY2019Q4	us-gaap	Noninterest Income NoninterestIncome	33297000	USD
CY2018Q4	us-gaap	Noninterest Income NoninterestIncome	23491000	USD
CY2019Q1	us-gaap	Noninterest Expense NoninterestExpense	56311000	USD
CY2018Q1	us-gaap	Noninterest Expense NoninterestExpense	53451000	USD
CY2019Q2	us-gaap	Noninterest Expense NoninterestExpense	93032000	USD
CY2018Q2	us-gaap	Noninterest Expense NoninterestExpense	52688000	USD
CY2019Q3	us-gaap	Noninterest Expense NoninterestExpense	67533000	USD
CY2018Q3	us-gaap	Noninterest Expense NoninterestExpense	55439000	USD
CY2019Q4	us-gaap	Noninterest Expense NoninterestExpense	67445000	USD
CY2018Q4	us-gaap	Noninterest Expense NoninterestExpense	64391000	USD
CY2019Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	11522000	USD
CY2018Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	6828000	USD
CY2019Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	10007000	USD
CY2018Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	9249000	USD
CY2019Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	17036000	USD
CY2018Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	9969000	USD
CY2019Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14368000	USD
CY2018Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	8258000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	35225000	USD
CY2018Q1	us-gaap	Net Income Loss NetIncomeLoss	27555000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	30628000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	31118000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	51845000	USD
CY2018Q3	us-gaap	Net Income Loss NetIncomeLoss	33015000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	47477000	USD
CY2018Q4	us-gaap	Net Income Loss NetIncomeLoss	29934000	USD
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.25
CY2018Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.00
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.89
CY2018Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.13
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.51
CY2018Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.20
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.38
CY2018Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.08
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.25
CY2018Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.00
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.89
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.13
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.51
CY2018Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.20
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.38
CY2018Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.07
CY2019Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	28106184	shares
CY2018Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	27486573	shares
CY2019Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	34313492	shares
CY2018Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	27526653	shares
CY2019Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	34361176	shares
CY2018Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	27537841	shares
CY2019Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	34374953	shares
CY2018Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	27815437	shares
CY2019Q1	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	54466	shares
CY2018Q1	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	67381	shares
CY2019Q2	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	41878	shares
CY2018Q2	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	54525	shares
CY2019Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	39390	shares
CY2018Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	63499	shares
CY2019Q4	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	46245	shares
CY2018Q4	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	58576	shares
CY2019Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	28160650	shares
CY2018Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	27553954	shares
CY2019Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34355370	shares
CY2018Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	27581178	shares
CY2019Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34400566	shares
CY2018Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	27601340	shares
CY2019Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34421198	shares
CY2018Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	27874013	shares
CY2019Q3	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	951000	USD
CY2019Q1	indb	Total Unusualorinfrequent Income Items TotalUnusualorinfrequentIncomeItems	0	USD
CY2018Q1	indb	Total Unusualorinfrequent Income Items TotalUnusualorinfrequentIncomeItems	0	USD
CY2019Q2	indb	Total Unusualorinfrequent Income Items TotalUnusualorinfrequentIncomeItems	0	USD
CY2018Q2	indb	Total Unusualorinfrequent Income Items TotalUnusualorinfrequentIncomeItems	0	USD
CY2019Q3	indb	Total Unusualorinfrequent Income Items TotalUnusualorinfrequentIncomeItems	951000	USD
CY2018Q3	indb	Total Unusualorinfrequent Income Items TotalUnusualorinfrequentIncomeItems	0	USD
CY2019Q4	indb	Total Unusualorinfrequent Income Items TotalUnusualorinfrequentIncomeItems	0	USD
CY2018Q4	indb	Total Unusualorinfrequent Income Items TotalUnusualorinfrequentIncomeItems	0	USD
CY2019Q1	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	1032000	USD
CY2018Q1	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	0	USD
CY2019Q2	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	24696000	USD
CY2018Q2	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	434000	USD
CY2019Q3	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	705000	USD
CY2018Q3	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	2688000	USD
CY2019Q4	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	0	USD
CY2018Q4	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	8046000	USD
CY2019Q1	indb	Adjustmentfortaxeffectofpreviouslyincurred M Aexpense AdjustmentfortaxeffectofpreviouslyincurredMAexpense	650000	USD
CY2019Q1	indb	Totalunusualorinfrequentexpenseitems Totalunusualorinfrequentexpenseitems	1682000	USD
CY2018Q1	indb	Totalunusualorinfrequentexpenseitems Totalunusualorinfrequentexpenseitems	0	USD
CY2019Q2	indb	Totalunusualorinfrequentexpenseitems Totalunusualorinfrequentexpenseitems	24696000	USD
CY2018Q2	indb	Totalunusualorinfrequentexpenseitems Totalunusualorinfrequentexpenseitems	434000	USD
CY2019Q3	indb	Totalunusualorinfrequentexpenseitems Totalunusualorinfrequentexpenseitems	705000	USD
CY2018Q3	indb	Totalunusualorinfrequentexpenseitems Totalunusualorinfrequentexpenseitems	2688000	USD
CY2019Q4	indb	Totalunusualorinfrequentexpenseitems Totalunusualorinfrequentexpenseitems	0	USD
CY2018Q4	indb	Totalunusualorinfrequentexpenseitems Totalunusualorinfrequentexpenseitems	8046000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	41170000	USD
CY2017Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	52458000	USD
CY2019	us-gaap	Loans And Leases Receivable Related Parties Additions LoansAndLeasesReceivableRelatedPartiesAdditions	49771000	USD
CY2018	us-gaap	Loans And Leases Receivable Related Parties Additions LoansAndLeasesReceivableRelatedPartiesAdditions	14862000	USD
CY2019	us-gaap	Loans And Leases Receivable Related Parties Proceeds LoansAndLeasesReceivableRelatedPartiesProceeds	35111000	USD
CY2018	us-gaap	Loans And Leases Receivable Related Parties Proceeds LoansAndLeasesReceivableRelatedPartiesProceeds	14057000	USD
CY2019	us-gaap	Loans And Leases Receivable Related Parties Period Increase Decrease LoansAndLeasesReceivableRelatedPartiesPeriodIncreaseDecrease	0	USD
CY2018	us-gaap	Loans And Leases Receivable Related Parties Period Increase Decrease LoansAndLeasesReceivableRelatedPartiesPeriodIncreaseDecrease	-12093000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	55830000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	41170000	USD
CY2019	us-gaap	Related Party Transaction Amounts Of Transaction RelatedPartyTransactionAmountsOfTransaction	7000000.0	USD
CY2019	indb	Nonaccrual Tdr Loanswithrelatedparties NonaccrualTDRLoanswithrelatedparties	0	USD
CY2019Q4	us-gaap	Related Party Deposit Liabilities RelatedPartyDepositLiabilities	13000000.0	USD
CY2018Q4	us-gaap	Related Party Deposit Liabilities RelatedPartyDepositLiabilities	10800000	USD
CY2019	indb	Leaseswithrelatedparties Leaseswithrelatedparties	0	USD

Files In Submission

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snlstockperformancegraph.jpg	Edgar Link	pending

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$INDB
INDEPENDENT BANK CORP Stock $indb

2018 Q4 Form 10-K Financial Statement

#000077690120000064 Filed on February 27, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$INDB INDEPENDENT BANK CORP Stock $indb

2018 Q4 Form 10-K Financial Statement

#000077690120000064 Filed on February 27, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$INDB
INDEPENDENT BANK CORP Stock $indb