Leases (Summary Of Lease Costs) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Amortization of property and equipment	$ 771,000
Interest expense on finance leases	124,000
Total finance lease expense	895,000
Operating lease expense	6,624,000	[1]	$ 6,400,000	$ 4,900,000
Sublease income	(905,000)
Total lease expense	$ 6,614,000

[1] Total rental expense for operating leases was $6.4 million in 2018 and $4.9 million in 2017.