Employee Pension Plans (Summary Of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Summary of net periodic benefit cost
Interest cost	$ 758	$ 948	$ 2,273	$ 2,844
Expected return on plan assets	(1,006)	(1,043)	(3,017)	(3,129)
Amortization of net loss	592	463	1,775	1,389
Other	231	225	694	675
Net periodic benefit cost	$ 575	$ 593	$ 1,725	$ 1,779