Other Income - Net (Schedule Of Other Income/(Expense)- Net) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Income - Net [Abstract]
Market value adjustment on assets held in deferred compensation trust	$ 1,417	$ 1,656	$ 5,619	$ 1,857
Loss on disposal of property and equipment	(146)	(134)	(481)	(224)
Interest income	51	119	297	301
Other - net	1	(1)	4	(1)
Total other income - net	$ 1,323	$ 1,640	$ 5,439	$ 1,933