Summary Of Significant Accounting Policies (Impact Of Adoption Of ASC 842 And ASC 606 On The Statements Of Income And Balance Sheet) (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2020		Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019		Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Costs and expenses											$ 139,175	$ 267,645	$ 285,307
Depreciation and amortization											22,317	22,747	22,275
General and administrative											16,998	25,395	27,337
Interest expense, net											9,354	7,904	6,837
Revenue	$ 15,021	[1]	$ 10,191	$ 3,422	$ 49,228	$ 68,880	[1]	$ 70,386	$ 76,009	$ 61,493	77,862	276,768	308,931
Income tax (benefit) expense											4,967	(28,837)	(3,298)
Net income (loss)	(17,663)	[1]	(19,352)	(22,887)	(5,955)	(27,458)	[1]	801	2,294	(2,140)	(65,857)	(26,503)	14,166
Operating property, net	353,125					258,138					353,125	258,138		$ 258,037
Intangible assets	3,971					4,320					3,971	4,320		3,827
Operating lease right-of-use assets	220,503					229,879					220,503	229,879		232,319
Deferred tax asset, net	3,362					3,444					3,362	3,444		26,526
Other current liabilities	3,826					3,653					3,826	3,653
Operating lease liabilities - current	22,699					20,379					22,699	20,379		245,280
Other liabilities	22,017					18,854					22,017	18,854		12,898
Operating lease liabilities - non-current	212,806					223,164					212,806	223,164
Deferred revenue	10,133					11,324					10,133	11,324
Retained earnings (deficit)	(44,553)					20,647					(44,553)	20,647		$ 47,076
Balance Without Adoption Of ASC 842 [[Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Depreciation and amortization											22,224	22,582
General and administrative											17,098	25,569
Interest expense, net											9,346	7,891
Income tax (benefit) expense											4,914	(28,819)
Net income (loss)											(65,966)	(26,541)
Operating property, net	353,013					257,933					353,013	257,933
Intangible assets	6,275					7,523					6,275	7,523
Deferred tax asset, net	3,352					3,380					3,352	3,380
Other current liabilities	4,006					3,789					4,006	3,789
Other liabilities	38,855					35,276					38,855	35,276
Retained earnings (deficit)	81,008					139,578					81,008	139,578
Effect Of Change Higher/(Lower) [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Depreciation and amortization											93	165
General and administrative											(100)	(174)
Interest expense, net											8	13
Income tax (benefit) expense											(53)	(18)
Net income (loss)											109	38
Operating property, net	112					205					112	205
Intangible assets	(2,304)					(3,203)					(2,304)	(3,203)
Operating lease right-of-use assets	220,503					229,879					220,503	229,879
Deferred tax asset, net	10					64					10	64
Other current liabilities	(180)					(136)					(180)	(136)
Operating lease liabilities - current	22,699					20,379					22,699	20,379
Other liabilities	(16,838)					(16,422)					(16,838)	(16,422)
Operating lease liabilities - non-current	212,806					223,164					212,806	223,164
Retained earnings (deficit)	165					38					165	38
Cinema [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Costs and expenses											91,065	210,050	225,791
Revenue											67,014	262,189	293,723
Cinema [Member] | Balance Without Adoption Of ASC 842 [[Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Costs and expenses											91,228	210,110
Cinema [Member] | Effect Of Change Higher/(Lower) [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Costs and expenses											(163)	(60)
As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	15,021	[1]	10,191	3,422	49,228	68,880	[1]	70,456	76,096	61,551
Net income (loss)	(17,663)	[1]	$ (19,352)	$ (22,887)	$ (5,955)	(27,458)	[1]	$ 852	$ 2,357	$ (2,097)
Operating property, net	353,125					258,138					353,125	258,138	257,667
Intangible assets	3,971					4,320					3,971	4,320	7,369
Operating lease right-of-use assets	220,503					229,879					220,503	229,879
Deferred tax asset, net	3,362					3,444					3,362	3,444	26,444
Other current liabilities	3,826					3,653					3,826	3,653
Operating lease liabilities - current	22,699					20,379					22,699	20,379
Other liabilities	22,017					18,854					22,017	18,854	28,931
Operating lease liabilities - non-current	212,806					223,164					212,806	223,164
Retained earnings (deficit)	$ 81,173					$ 139,616					$ 81,173	$ 139,616	$ 47,048

[1] Since previously published financial statements have been corrected, there is no impact on the fourth quarter results for 2019 or for the full year of 2020 and so no data is displayed here.