XML 128 R100.htm IDEA: XBRL DOCUMENT v3.10.0.1
Retirement Plans (Funded Status of Retirement Income Plan and Retirement Life Plan) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Supplemental Employee Retirement Plan [Member]      
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) $ 400 $ 400 $ 500
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]      
Benefit obligation, beginning of year 10,100    
Benefit obligation, end of year 9,500 10,100  
Retirement Income Plan [Member]      
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) (8,358) (4,928) 2,973
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]      
Benefit obligation, beginning of year 364,411 330,588  
Service cost 0 0 1,647
Interest cost 12,428 12,490 12,336
Actuarial losses (gains) (31,738) 31,158  
Benefits paid fair value (10,422) (9,825)  
Benefit obligation, end of year 334,679 364,411 330,588
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]      
Fair value of assets, beginning of year 363,673 316,515  
Actual return on plan assets, net of expenses (21,571) 46,983  
Contributions by the employer to funded plans 0 10,000  
Fair value of assets, end of year 331,680 363,673 316,515
Funded status (2,999) (738)  
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]      
Liabilities (2,999) (738)  
Net pension liability, end of year (2,999) (738)  
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]      
Net actuarial loss 98,057 87,438  
Total 98,057 87,438  
Weighted-Average Liability Asumptions      
Accumulated benefit obligation $ 334,679 $ 364,411  
Discount rate 4.46% 3.78%  
Retirement Life Plan [Member]      
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) $ 300 $ 300 $ 300
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]      
Benefit obligation, beginning of year 6,400    
Benefit obligation, end of year $ 5,800 $ 6,400