Summary Of Significant Accounting Policies (Schedule Of Other Operating Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other operating income	$ (987)	$ 75,095	$ (9,132)
CARES Act Grant [Member]
Other operating income		80,225
Lost Revenue [Member] | CARES Act Grant [Member]
Other operating income		44,784
Incremental PTO [Member] | CARES Act Grant [Member]
Other operating income		21,425
Hard Costs [Member] | CARES Act Grant [Member]
Other operating income		$ 14,016