Summary Of Significant Accounting Policies (Schedule Of Allowance For Doubtful Accounts) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Period	[1]	$ 788	$ 1,371	$ 10,085
Charges to Operations	[1]	489	0	2,160
Deductions	[1]	(763)	(583)	(10,874)
Balance at End of Period	[1]	$ 514	$ 788	$ 1,371

[1] Deductions in the allowance for doubtful accounts represent write-offs, net of recoveries, of amounts determined to be uncollectible.