Property Plant and Equipment (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Property, plant and equipment
Cost	$ 170,955	$ 153,000
Accumulated Depreciation	81,858	78,965
Net Book Value	89,097	74,035
Other property, plant and equipment [Member]
Property, plant and equipment
Cost	53,141	52,091
Accumulated Depreciation	40,048	39,182
Net Book Value	13,093	12,909
Land [Member]
Property, plant and equipment
Cost	1,593	1,593
Accumulated Depreciation	0	0
Net Book Value	1,593	1,593
Building [Member]
Property, plant and equipment
Cost	14,723	14,723
Accumulated Depreciation	9,157	8,906
Net Book Value	5,566	5,817
Office and Production Equipment [Member]
Property, plant and equipment
Cost	28,051	27,172
Accumulated Depreciation	23,671	23,454
Net Book Value	4,380	3,718
Leasehold Improvements [Member]
Property, plant and equipment
Cost	8,774	8,603
Accumulated Depreciation	7,220	6,822
Net Book Value	1,554	1,781
Asset under Construction [Member]
Property, plant and equipment
Cost	12,719	8,305
Accumulated Depreciation	0	0
Net Book Value	12,719	8,305
Equipment leased or held for use [Member]
Property, plant and equipment
Cost	105,095	92,604
Accumulated Depreciation	41,810	39,783
Net Book Value	63,285	52,821
Theater System Components [Member]
Property, plant and equipment
Cost	98,740	86,249
Accumulated Depreciation	35,762	33,775
Net Book Value	62,978	52,474
Camera Equipment [Member]
Property, plant and equipment
Cost	6,355	6,355
Accumulated Depreciation	6,048	6,008
Net Book Value	$ 307	$ 347