XML 105 R94.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Income Taxes - Narrative (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Operating Loss Carryforwards [Line Items] |  |  |
State tax, net of federal income tax | $ 6,362 | $ 3,285 | $ 3,056
Net deferred tax asset | 23,236 | 20,883 |
Bad debt base year reserve | 5,900 | 5,900 |
Federal tax bad debt deferred tax liability | 2,800 | 2,800 |
Accounting Standards Update 2016-13 |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Deferred tax assets | $ 1,200 |  |
New Jersey Division of Taxation |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
State tax, net of federal income tax |  | 889 |
Victory |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Net deferred tax asset |  | $ 1,400 |

X
- Definition Amount Of Bad Debts Reserved For In Current Year + References No definition available. + Details
Name: | nfbk_AmountOfBadDebtsReservedForInCurrentYear
Namespace Prefix: | nfbk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Federal Tax Bad Debt Deferred Tax Liability + References No definition available. + Details
Name: | nfbk_FederalTaxBadDebtDeferredTaxLiability
Namespace Prefix: | nfbk_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred income. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32632-109319 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32621-109319 + Details
Name: | us-gaap_DeferredTaxAssetsDeferredIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32537-109319 + Details
Name: | us-gaap_DeferredTaxAssetsLiabilitiesNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to state and local income tax expense (benefit). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319 + Details
Name: | us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_OperatingLossCarryforwardsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201613Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityNameAxis=us-gaap_NewJerseyDivisionOfTaxationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=nfbk_VictoryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |