Share-Based Compensation And Stock Repurchase Plans (Summary Of Stock Options Outstanding And Exercisable) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Stock Options, Granted		0	0
Weighted Average Exercise Price of Options Outstanding, Granted	$ 1.92
Weighted Average Remaining Years of Contractual Life	1 year 9 months 14 days	1 year 2 months 26 days	1 year 7 months 28 days	2 years 2 months 4 days
Aggregate Intrinsic Value, Beginning balance			$ 13,969
Aggregate Intrinsic Value, Exercised			$ 63,831
Aggregate Intrinsic Value, Ending balance				$ 13,969
Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Stock Options, Beginning balance	327,498	517,344	713,479
Number of Stock Options, Granted	207,657
Number of Stock Options, Exercised			(38,803)
Number of Stock Options, Expired	(122,376)	(189,846)	(157,332)
Number of Stock Options Outstanding, Ending balance	412,779	327,498	517,344	713,479
Weighted Average Exercise Price of Options Outstanding, Beginning price	$ 15.87	$ 15.42	$ 14.64
Weighted Average Exercise Price of Options Outstanding, Granted	1.92
Weighted Average Exercise Price of Options Outstanding, Exercised			4.66
Weighted Average Exercise Price of Options Outstanding, Expired		14.63	11.87
Weighted Average Exercise Price of Options Outstanding, Ending price	$ 14.19	$ 15.87	$ 15.42	$ 14.64

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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