Benefit Plans (Targeted asset allocation of plan assets and the actual allocation of plan assets) (Details)
Mar. 31, 2020
Equity Securities  
Defined Benefit Plan Disclosure [Line Items]  
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage 75.00%
Debt Securities  
Defined Benefit Plan Disclosure [Line Items]  
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage 25.00%