Investment in National CineMedia (Details Textual) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Schedule Of Investment In Balance Sheet And Income Statement Location (Additional Textual) [Abstract]
Investment in NCM - receipt of common units (see Note 6)	$ 9,137	$ 9,302
Investment in National CineMedia (Textual) [Abstract]
Equity income/loss from NCM	716	904
Number of additional common units of NCM received under common unit adjustment agreement	598,724
Total number of common units of NCM owned by Company	18,094,644
Interest on common units of NCM owned by company	16.00%
Company's beverage concessionaire	2,722
Remaining term of exhibitor services agreement			24 years
Deferred Revenue [Member]
Schedule Of Investment In Balance Sheet And Income Statement Location (Additional Textual) [Abstract]
Investment in NCM - receipt of common units (see Note 6)	$ (9,137)