Derivative Instruments and Hedging Activities - Interest Rate Swap Agreements (Details) - Not Designated as Hedging Instrument - Interest Rate Swap - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Derivative [Line Items]
Notional amount	$ 172,026	$ 176,637	$ 166,329
Other Assets
Derivative [Line Items]
Derivative asset	2,287	5,080	6,366
Other Liabilities
Derivative [Line Items]
Derivative liability	$ 2,287	$ 5,080	$ 6,366

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.

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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.

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Nominal or face amount used to calculate payment on derivative.

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