XML 55 R44.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Commitments and Contingencies (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract] |
Commitment And Contingent Liabilities Not Reflected In Consolidated Financial Statements | At December 31, 2021 and 2020, the following commitment and contingent liabilities existed that are not reflected in the accompanying consolidated financial statements (in thousands):
| December 31,
| 2021 |  | 2020
Commitments to extend credit | $ | 159,403 |  |  | $ | 81,288 |
Unused lines of credit | 245,860 |  |  | 153,960 |
Standby letters of credit | 3,266 |  |  | 3,313 |

X
- Definition Schedule Of Commitments And Contingencies Table [Text Block] + References No definition available. + Details
Name: | nfbk_ScheduleOfCommitmentsAndContingenciesTableTableTextBlock
Namespace Prefix: | nfbk_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

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