Fair Value Measurements and Derivative Instruments (Schedule of Carrying Value and Estimated Fair Value of Long-Term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt	$ 179,315	$ 134,001
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of debt	$ 180,235	$ 134,288