Restructuring Charges (Schedule Of Accrued Restructuring) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Restructuring Cost And Reserve [Line Items]
Beginning Balance	$ 4,454
Restructuring charges	1,591
Cash Payment	(2,528)
Non-Cash Activity	(42)
Ending Balance	3,475
Severance [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	3,996
Restructuring charges	546
Cash Payment	(1,913)
Non-Cash Activity	(29)
Ending Balance	2,600
Lease Facility Costs [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	50
Restructuring charges	475
Cash Payment	(512)
Non-Cash Activity	(13)
Other Exit Costs [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	408
Restructuring charges	570
Cash Payment	(103)
Ending Balance	$ 875