Derivatives And Risk Management (Interest Rate Swap Agreements) (Details) - Interest Rate Swap [Member] $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019 USD ($) Caontracts	Dec. 31, 2018 USD ($) Caontracts
2019
Derivatives, Fair Value [Line Items]
Number of Interest Rate Derivatives Held | Caontracts	6	6
Derivative, Notional Amount | $	$ 70,000	$ 70,000
Mandatory Cash Settlement Date	2019	2019
2020
Derivatives, Fair Value [Line Items]
Number of Interest Rate Derivatives Held | Caontracts	6	6
Derivative, Notional Amount | $	$ 60,000	$ 60,000
Mandatory Cash Settlement Date	2020	2020
2021
Derivatives, Fair Value [Line Items]
Number of Interest Rate Derivatives Held | Caontracts	3	2
Derivative, Notional Amount | $	$ 35,000	$ 25,000
Mandatory Cash Settlement Date	2021	2021
2022
Derivatives, Fair Value [Line Items]
Number of Interest Rate Derivatives Held | Caontracts	9	7
Derivative, Notional Amount | $	$ 100,000	$ 80,000
Mandatory Cash Settlement Date	2022	2022