v3.19.3
Fair Value (Schedule Of Carrying Amounts And Fair Values Of Financial Assets/Liabilities) (Details) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Energy Related Derivative [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Liability $ (17,800)  
Fair Value, Inputs, Level 1 [Member] | Commodity Contract [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Asset 4,839  
Fair Value, Inputs, Level 2 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt (5,185,750) $ (4,224,373)
Fair Value, Inputs, Level 2 [Member] | Interest Rate Contract [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Liability   (8,126)
Fair Value, Inputs, Level 2 [Member] | Energy Related Derivative [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Liability (17,755)  
Fair Value, Inputs, Level 3 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term receivables 20,789 20,844
Guarantees, Fair Value Disclosure (408) (16,409)
Reported Value Measurement [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term receivables 20,789 20,844
Guarantees, Fair Value Disclosure (408) (16,409)
Debt (4,705,775) (4,270,869)
Reported Value Measurement [Member] | Commodity Contract [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Asset 4,839 55,011
Reported Value Measurement [Member] | Interest Rate Contract [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Liability   (8,126)
Reported Value Measurement [Member] | Energy Related Derivative [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Liability (17,755)  
Estimate of Fair Value Measurement [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term receivables 20,789 20,844
Guarantees, Fair Value Disclosure (408) (16,409)
Debt (5,185,750) (4,224,373)
Estimate of Fair Value Measurement [Member] | Commodity Contract [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Asset 4,839 55,011
Estimate of Fair Value Measurement [Member] | Interest Rate Contract [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Liability   (8,126)
Estimate of Fair Value Measurement [Member] | Energy Related Derivative [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Liability $ (17,755)  
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commodity Contract [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Derivative Asset   $ 55,011