Leases (Components Of Lease Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Amortization of right-of-use assets	$ 15	$ 40	$ 79	$ 121
Interest on lease liabilities	2	3	6	10
Operating lease cost	8,136	7,773	24,447	23,339
Variable lease cost	(1,747)	320	(2,428)	1,174
Total lease cost	$ 6,406	$ 8,136	$ 22,105	$ 24,644