Leases (Schedule Of Lease Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Fixed rental costs	$ 6,809	$ 7,460
Short-term lease cost	1,807	5,113
Variable lease cost	1,917	2,490
Total operating lease costs	$ 10,533	$ 15,063