Stockholders' Equity And Stock-Based Compensation (Summary Of Stock-Based Compensation Expense By Type) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Total stock-based compensation expense	$ 1,713	$ 2,448	$ 3,720	$ 9,413
Time-Based Options [Member]
Total stock-based compensation expense	1,445	1,917	3,252	3,686
Performance Shares [Member]
Total stock-based compensation expense	132	387	215	5,528
ESPP [Member]
Total stock-based compensation expense	$ 136	$ 144	$ 253	$ 199