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]
Operating lease expense	$ 1,484	$ 1,495	$ 4,134	$ 4,367
Finance lease expense:
Amortization of right-of-use assets	39	142	120	203
Interest on lease liabilities	3	20	11	31
Total finance lease expense	42	162	131	234
Short-term lease expense	55	132	209	679
Variable lease expense	$ 543	$ 904	$ 1,112	$ 2,614