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Derivatives and Hedging Activities - Additional Information (Details) - Interest Rate Swap | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 USD ($) derivative loan | Dec. 31, 2019 USD ($) loan derivative | Oct. 31, 2018 USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Participating Mortgage Loans, Mortgage Obligations, Amount | $ 27,700,000 | $ 37,400,000 |
Number of Participation loans purchased | loan | 4 | 5 |
Cash flow hedges |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Derivative, Notional Amount |  |  | $ 400,000,000
Derivative, Fixed Interest Rate |  |  | 3.018%
Expected interest income on termination | $ 2,000,000.0 |  |
Not Designated as Hedging Instrument |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Number of Interest Rate Derivatives Held | derivative | 19 | 19 |
Valley Bank | Not Designated as Hedging Instrument |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Derivative, Notional Amount | $ 584,000 |  |
Number of Interest Rate Derivatives Held | derivative | 2 |  |

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- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959 + Details
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