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, 2016 USD ($)	[1]	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	[1]	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) segment	Dec. 31, 2015 USD ($)		Dec. 31, 2014 USD ($)
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total revenue		$ 67,451		$ 71,315	$ 66,918	$ 64,789	$ 66,691		$ 57,788	$ 72,802	$ 60,584	$ 270,473	$ 257,865	[2],[3]	$ 255,242	[2],[3]
Cost of services and products (excluding depreciation and amortization)												(207,567)	(200,955)	[2]	(198,205)	[2]
Depreciation and amortization												(15,689)	(14,562)	[3]	(15,468)	[3]
General and administrative expense												(26,906)	(18,652)	[3]	(18,902)	[3]
Total costs and expenses												(250,162)	(234,169)	[3]	(232,575)	[3]
Operating income												$ 20,311	23,696	[3]	22,667	[3]
Number of segments | segment												2
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total revenue												$ 277,839	264,402	[2]	262,703	[2]
Cost of services and products (excluding depreciation and amortization)												(214,933)	(207,492)	[2]	(205,666)	[2]
Depreciation and amortization												(15,294)	(14,268)	[2]	(15,108)	[2]
Total costs and expenses												(228,046)	(218,951)	[2]	(217,930)	[2]
Operating income												42,427	38,914	[2],[4]	37,312	[2],[4]
Inter-segment Elimination [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total revenue	[5]											(7,366)	(6,537)	[2]	(7,461)	[2]
Total costs and expenses	[5]											(7,366)	(6,537)	[2]	(7,461)	[2]
Cinema Exhibition [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total revenue												256,922	242,823		238,355
Cost of services and products (excluding depreciation and amortization)												(205,889)	(196,544)		(195,896)
Cinema Exhibition [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total revenue												256,922	242,823		238,355
Cost of services and products (excluding depreciation and amortization)												(205,889)	(196,544)		(195,896)
Depreciation and amortization												(11,772)	(11,161)		(11,047)
Total costs and expenses												(221,424)	(210,705)		(210,518)
Operating income												35,498	32,118		27,837
Real Estate [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total revenue												20,917	21,579		24,348
Cost of services and products (excluding depreciation and amortization)												(9,044)	(10,948)		(9,770)
Real Estate [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total revenue												20,917	21,579		24,348
Cost of services and products (excluding depreciation and amortization)												(9,044)	(10,948)		(9,770)
Depreciation and amortization												(3,522)	(3,107)		(4,061)
Total costs and expenses												(13,988)	(14,783)		(14,873)
Operating income												6,929	6,796		9,475
Segment [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
General and administrative expense												(5,185)	(3,728)	[2]	(4,617)	[2]
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												(3,763)	(3,000)		(3,575)
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												$ (1,422)	$ (728)		$ (1,042)

[1] Fourth Quarter Results included the impact as a result of a change in accounting principle (see Note 2 - Summary of Significant Accounting Policies - Accounting Changes).

[2] Balances relating to Cinema segment included the restatement impact as a result of a change in accounting principle (see Note 2 - Summary of Significant Accounting Policies - Accounting Changes).

[3] Certain 2015 and 2014 balances included the restatement impact as a result of a change in accounting principle (see Note 2 - Summary of Significant Accounting Policies - Accounting Changes).

[4] 2015 and 2014 balances included the restatement impact as a result of a change in accounting principle (see Note 2 - Summary of Significant Accounting Policies - Accounting Changes).

[5] Inter-segment eliminations relate to the internal charge between the two segments where the cinema operates within real estate owned within the group.