v3.10.0.1
Employee Benefit Plans (Amounts Recognized In Consolidated Balance Sheets) (Details) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Amounts recognized in consolidated balance sheet:        
Long-term pension and benefit cost $ 122,580 $ 111,305    
Accumulated other comprehensive loss:        
Accumulated Other Comprehensive Income (Loss), Net of Tax (120,491) (137,578)    
Pension Plan [Member]        
Amounts recognized in consolidated balance sheet:        
Current accrued benefit cost 0 0    
Long-term pension and benefit cost 111,359 99,170    
Net amount recognized in consolidated balance sheet 111,359 99,170    
Accumulated other comprehensive loss:        
Net actuarial loss (91,669) (100,474)    
Prior service credit 3,067 3,248    
Accumulated Other Comprehensive Income (Loss), Net of Tax (88,602) (97,226) $ (58,584) $ (62,279)
Amount of Liabilities and Accumulated Other Comprehensive Loss Recognized in Consolidated Balance Sheet 22,757 1,944    
Other Postretirement Benefits [Member]        
Amounts recognized in consolidated balance sheet:        
Current accrued benefit cost 859 625    
Long-term pension and benefit cost 11,221 12,135    
Net amount recognized in consolidated balance sheet 12,080 12,760    
Accumulated other comprehensive loss:        
Net actuarial loss (5,409) (6,597)    
Prior service credit 0 0    
Accumulated Other Comprehensive Income (Loss), Net of Tax (5,409) (6,597) $ (7,881) $ (3,945)
Amount of Liabilities and Accumulated Other Comprehensive Loss Recognized in Consolidated Balance Sheet $ 6,671 $ 6,163