Discontinued Operations (Summary Of Results Of Discontinued Operations) (Details) - Cardiac Diagnostic Monitoring Business [Member] - Discontinued Operations, Disposed of by Sale [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Sales, net	$ 140	$ 1,161	$ 1,212
Operating costs and expenses	(268)	(2,135)	(2,177)
Loss on impairment		(796)
Net loss from discontinued operations	$ (128)	$ (1,770)	$ (965)