Description Of Business And Segment Reporting (Summary Of Results Of Operations For Principal Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	$ 10,191	$ 70,386	$ 62,841	$ 207,886
Segment operating income (loss)	(17,375)	2,840	(46,610)	7,209
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	10,191	70,386	62,841	207,886
Segment operating income (loss)	(14,254)	7,436	(34,782)	21,702
Intersegment Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	(171)	(1,808)	(1,953)	(5,524)
Cinema Exhibition [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	7,339	66,663	54,866	196,885
Segment operating income (loss)	(13,410)	5,951	(33,318)	17,715
Real Estate [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	3,023	5,531	9,928	16,525
Segment operating income (loss)	$ (844)	$ 1,485	$ (1,464)	$ 3,987