Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Estimated Fair Value Of Other Financial Assets And Liabilities) (Details)

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Fair Value Measurements (Estimated Fair Value Of Other Financial Assets And Liabilities) (Details) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Long-term debt, including current portion, estimated fair value $ 162,275 $ 204,910
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Long-term debt, including current portion, estimated fair value 0 0
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Long-term debt, including current portion, estimated fair value 159,367 203,938
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Long-term debt, including current portion, estimated fair value $ 0 $ 0