XML 123 R108.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Fair Value Measurements (Schedule Of Fair Value Disclosures) (Details) - USD ($)
$ in Thousands
Dec. 31, 2019
Dec. 31, 2018
US States and Political Subdivisions Debt Securities [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Credit loss recognized $ 31,000 $ 31,000
Investments, Held To Maturity [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Held-to-maturity securities, accumulated unrecognized holding loss   12
Fair Value [Member] | Fixed-Rate Debt [Member] | Fair Value Using Significant Unobservable Inputs (Level 3) [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt 1,787,663 1,761,215
Fair Value [Member] | Variable Rate Debt [Member] | Fair Value Using Significant Unobservable Inputs (Level 3) [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt 17,426 23,131
Fair Value [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value Using Significant Unobservable Inputs (Level 3) [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investments 25,000 25,000
Fair Value [Member] | Investments, Held To Maturity [Member] | Significant Other Observable Inputs (Level 2) [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investments   2,988
Carrying Value [Member] | Fixed-Rate Debt [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt 1,714,890 1,771,999
Carrying Value [Member] | Variable Rate Debt [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt 17,448 22,685
Carrying Value [Member] | US States and Political Subdivisions Debt Securities [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investments $ 17,277 20,009
Carrying Value [Member] | Investments, Held To Maturity [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investments   $ 3,000