Revenues (Reconciliation Of Deferred Revenue) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenues balance at December 31, 2017	$ 1,355	$ 1,451
Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenues balance at December 31, 2017		2,056
Cumulative effect of adoption of Topic 606		(605)
Deferred revenues balance at January 1, 2018		$ 1,451