Leases (Schedule Of Base And Contingent Rental Expenses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
Base rent expense	$ 31,630	$ 29,824	$ 30,565
Contingent rental expense	2,505	1,484	1,848
Total cinema rent expense	$ 34,135	$ 31,308	$ 32,413