Employee Pension Plans (Summary Of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Summary of net periodic benefit cost
Interest cost	$ 582	$ 758	$ 1,164	$ 1,516
Service cost	237	231	473	462
Expected return on plan assets	(1,015)	(1,006)	(2,030)	(2,012)
Recognized net actuarial losses	683	592	1,366	1,184
Net periodic benefit cost	$ 487	$ 575	$ 973	$ 1,150