XML 46 R34.htm IDEA: XBRL DOCUMENT v3.7.0.1
Benefit Plans (Schedule Of Benefit Plans) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Pension Costs        
Defined Benefit Plan Disclosure [Line Items]        
Service cost $ 496 $ 508 $ 992 $ 1,016
Interest cost 1,385 1,498 2,769 2,996
Expected return on plan assets (1,389) (1,310) (2,777) (2,620)
Net cost 492 696 984 1,392
Postretirement Costs        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 1 1 1 2
Interest cost 241 272 483 543
Net cost $ 242 $ 273 $ 484 $ 545