Commitments And Contingencies (Components Of Lease Expense) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies [Abstract]
Operating lease expense		$ 19,587	$ 20,771	$ 20,806
Variable lease expense	[1]	1,225	1,681	824
Total lease expense		$ 20,812	$ 22,452	$ 21,630

[1] Represents amounts incurred in excess of the minimum payments required for a certain building lease and for the handling and unloading of railcars for a certain land lease, offset by railcar lease abatements provided by the lessor when railcars are out of service during periods of maintenance or upgrade.