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Benefit Plans - Defined Benefit Plans - Estimated Net Actuarial Loss and Prior Service Cost (Details)
Dec. 31, 2020
USD ($)
Supplemental Retirement Plan  
Estimated net actuarial loss and prior service cost that will be amortized from accumulated other comprehensive loss into net periodic cost over next fiscal year  
Estimated net actuarial loss and prior service cost that will be amortized from accumulated other comprehensive loss into net periodic cost over next fiscal year $ 643,000
Split-Dollar Life Insurance Benefit Plan  
Estimated net actuarial loss and prior service cost that will be amortized from accumulated other comprehensive loss into net periodic cost over next fiscal year  
Estimated net actuarial loss and prior service cost that will be amortized from accumulated other comprehensive loss into net periodic cost over next fiscal year $ 90,000