Description Of Business And Segment Reporting (Summary Of Results Of Operations For Principal Business Segments) (Details) $ in Thousands		3 Months Ended										12 Months Ended
		Dec. 31, 2019 USD ($)	[1]	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	[1]	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue		$ 68,880		$ 70,386	$ 76,009	$ 61,493	$ 74,877		$ 74,150	$ 84,125	$ 75,779	$ 276,768	$ 308,931	$ 279,556
Depreciation and amortization												(22,747)	(22,275)	(16,942)
General and administrative expense												(25,395)	(27,337)	(25,347)
Total costs and expenses												(267,645)	(285,307)	(259,173)
Segment operating income (loss)												$ 9,123	23,624	20,383
Number of segments | segment												2
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue												$ 284,094	317,958	287,129
Total of services and products (excluding depreciation and amortization)												(226,829)	(244,722)	(224,456)
Depreciation and amortization												(22,333)	(21,881)	(16,469)
Total costs and expenses												(255,624)	(272,653)	(246,326)
Segment operating income (loss)												28,470	45,305	40,803
Inter-segment Elimination [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	[2]											(7,326)	(9,027)	(7,573)
Total costs and expenses	[2]											7,326	9,027	7,573
Cinema Exhibition [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue												262,189	293,723	263,141
Total of services and products (excluding depreciation and amortization)												(217,376)	(234,818)	(215,020)
Depreciation and amortization												(16,940)	(16,314)	(12,213)
Total costs and expenses												(238,860)	(254,856)	(230,494)
Segment operating income (loss)												23,329	38,867	32,647
Cinema Exhibition [Member] | Inter-segment Elimination [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total of services and products (excluding depreciation and amortization)	[2]											(7,326)	(9,027)	(7,573)
Real Estate [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue												21,905	24,235	23,988
Total of services and products (excluding depreciation and amortization)												(9,453)	(9,904)	(9,436)
Depreciation and amortization												(5,393)	(5,567)	(4,256)
Total costs and expenses												(16,764)	(17,797)	(15,832)
Segment operating income (loss)												5,141	6,438	8,156
Real Estate [Member] | Inter-segment Elimination [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	[2]											(7,326)	(9,027)	(7,573)
Segment [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
General and administrative expense												(6,462)	(6,050)	(5,401)
Segment [Member] | Cinema Exhibition [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
General and administrative expense												(4,544)	(3,724)	(3,261)
Segment [Member] | Real Estate [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
General and administrative expense												(1,918)	(2,326)	(2,140)
Third Party [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue												276,768	308,931	279,556
Total of services and products (excluding depreciation and amortization)												(219,503)	(235,695)	(216,883)
Third Party [Member] | Cinema Exhibition [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue												262,189	293,723	263,141
Total of services and products (excluding depreciation and amortization)												(210,050)	(225,791)	(207,447)
Third Party [Member] | Real Estate [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue												14,579	15,208	16,415
Total of services and products (excluding depreciation and amortization)												$ (9,453)	$ (9,904)	$ (9,436)

[1] Since previously published financial statements have been corrected, there is no impact on the fourth quarter results for 2019 and so no data is displayed here.

[2] Inter-segment Revenues and Operating Expense relates to the internal charge between the two segments where the cinema operates within real estate owned within the group.