XML 87 R77.htm IDEA: XBRL DOCUMENT
v3.21.2

FAIR VALUE OF FINANCIAL INSTRUMENTS - Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020
Financial Assets |  |  |  |  |
Derivative assets | $ 41,700 |  | $ 41,700 |  | $ 18,932
Financial Liabilities |  |  |  |  |
Derivative liabilities | 38,889 |  | 38,889 |  | 37,374
Impaired Loans [Abstract] |  |  |  |  |
Individually evaluated CRE loans with an allowance for credit losses, Outstanding balance |  |  |  |  | 12,502
Valuation allowance |  |  |  |  | 6,474
Provision for credit losses | (5,187) | $ 5,931 | 6,344 | $ 20,003 |
Recurring | Cash flow hedges |  |  |  |  |
Financial Assets |  |  |  |  |
Derivative assets | 2,811 |  | 2,811 |  |
Financial Liabilities |  |  |  |  |
Derivative liabilities |  |  |  |  | 18,442
Recurring | Freestanding derivatives |  |  |  |  |
Financial Assets |  |  |  |  |
Derivative assets | 38,889 |  | 38,889 |  | 30,596
Financial Liabilities |  |  |  |  |
Derivative liabilities | 38,889 |  | 38,889 |  | 30,596
Recurring | Level 2 Inputs [Member] | Cash flow hedges |  |  |  |  |
Financial Assets |  |  |  |  |
Derivative assets | 2,811 |  | 2,811 |  |
Financial Liabilities |  |  |  |  |
Derivative liabilities |  |  |  |  | 18,442
Recurring | Level 2 Inputs [Member] | Freestanding derivatives |  |  |  |  |
Financial Assets |  |  |  |  |
Derivative assets | 38,889 |  | 38,889 |  | 30,596
Financial Liabilities |  |  |  |  |
Derivative liabilities | 38,889 |  | 38,889 |  | 30,596
Nonrecurring [Member] |  |  |  |  |
Impaired Loans [Abstract] |  |  |  |  |
Individually evaluated CRE loans with an allowance for credit losses, Outstanding balance | 63,900 |  | 63,900 |  |
Valuation allowance | 8,800 |  | 8,800 |  |
Provision for credit losses | 9,000 |  | 8,700 |  |
Carrying amount of impaired loans |  |  |  |  | 0
Nonrecurring [Member] | Level 3 Inputs [Member] |  |  |  |  |
Impaired Loans [Abstract] |  |  |  |  |
Individually evaluated loans | 55,146 |  | 55,146 |  |
Carrying Amount | Nonrecurring [Member] |  |  |  |  |
Impaired Loans [Abstract] |  |  |  |  |
Individually evaluated loans | 55,146 |  | 55,146 |  |
Agency Notes | Recurring |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: | 81,018 |  | 81,018 |  | 47,421
Agency Notes | Recurring | Level 2 Inputs [Member] |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: | 81,018 |  | 81,018 |  | 47,421
Treasury Securities | Recurring |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: | 247,696 |  | 247,696 |  |
Treasury Securities | Recurring | Level 2 Inputs [Member] |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: | 247,696 |  | 247,696 |  |
Corporate Securities | Recurring |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: | 126,833 |  | 126,833 |  | 64,461
Corporate Securities | Recurring | Level 2 Inputs [Member] |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: | 126,833 |  | 126,833 |  | 64,461
Pass-through MBS issued by GSEs | Recurring |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: |  |  |  |  | 143,483
Mortgage-backed securities | 621,957 |  | 621,957 |  |
Pass-through MBS issued by GSEs | Recurring | Level 2 Inputs [Member] |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: |  |  |  |  | 143,483
Mortgage-backed securities | 621,957 |  | 621,957 |  |
Agency Collateralized Mortgage Obligations ("CMOs") | Recurring |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: | 590,426 |  | 590,426 |  | 283,496
Agency Collateralized Mortgage Obligations ("CMOs") | Recurring | Level 2 Inputs [Member] |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: | 590,426 |  | 590,426 |  | 283,496
State and municipal obligations. | Recurring |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: | 41,133 |  | 41,133 |  |
State and municipal obligations. | Recurring | Level 2 Inputs [Member] |  |  |  |  |
Financial Assets |  |  |  |  |
Securities available-for-sale: | $ 41,133 |  | $ 41,133 |  |
Domestic Equity Mutual Funds | Recurring |  |  |  |  |
Financial Assets |  |  |  |  |
Marketable equity securities (Registered Mutual Funds) |  |  |  |  | 1,769
Domestic Equity Mutual Funds | Recurring | Level 1 Inputs [Member] |  |  |  |  |
Financial Assets |  |  |  |  |
Marketable equity securities (Registered Mutual Funds) |  |  |  |  | 1,769
International Equity Mutual Funds | Recurring |  |  |  |  |
Financial Assets |  |  |  |  |
Marketable equity securities (Registered Mutual Funds) |  |  |  |  | 468
International Equity Mutual Funds | Recurring | Level 1 Inputs [Member] |  |  |  |  |
Financial Assets |  |  |  |  |
Marketable equity securities (Registered Mutual Funds) |  |  |  |  | 468
Fixed Income Mutual Funds | Recurring |  |  |  |  |
Financial Assets |  |  |  |  |
Marketable equity securities (Registered Mutual Funds) |  |  |  |  | 3,733
Fixed Income Mutual Funds | Recurring | Level 1 Inputs [Member] |  |  |  |  |
Financial Assets |  |  |  |  |
Marketable equity securities (Registered Mutual Funds) |  |  |  |  | $ 3,733

X
- Definition Represents amount related to impaired loan financing receivables. + References No definition available. + Details
Name: | dcom_ImpairedLoanFinancingReceivableFairValueDisclosure
Namespace Prefix: | dcom_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | dcom_ImpairedLoansAbstract
Namespace Prefix: | dcom_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of individually evaluated loans. + References No definition available. + Details
Name: | dcom_IndividuallyEvaluatedLoansFairValueDisclosure
Namespace Prefix: | dcom_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents marketable equity securities. + References No definition available. + Details
Name: | dcom_MarketableEquitySecuritiesFairValueDisclosure
Namespace Prefix: | dcom_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 + Details
Name: | us-gaap_DerivativeLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of allowance for credit losses related to recorded investment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableRelatedAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of investment in impaired financing receivables for which there is a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953550-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale. + References No definition available. + Details
Name: | us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of expense related to estimated loss from loan and lease transactions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.11) -URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524 + Details
Name: | us-gaap_ProvisionForLoanAndLeaseLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=dcom_FreestandingDerivativesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_DomesticCorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=dcom_DomesticEquityMutualFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=dcom_InternationalEquityMutualFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=dcom_FixedIncomeMutualFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |