Other Operating Expenses/(Income) (Schedule Of Other Operating Expenses/(Income)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Total other operating expenses/(income)	$ (75,095)	$ 9,132	$ 1,300
CARES Act Grant Income [Member]
Total other operating expenses/(income)	(80,225)
Litigation Settlements [Member]
Total other operating expenses/(income)	4,589	6,000	796
Loss On Sale Of Transportation Equipment [Member]
Total other operating expenses/(income)		2,266
Loss On Disposal Of Property And Equipment [Member]
Total other operating expenses/(income)	$ 541	$ 866	$ 504