Property and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property and Equipment
Property and equipment, at cost	$ 27,881,000	$ 26,298,000
Accumulated depreciation and amortization	(18,082,000)	(15,843,000)
Property and equipment, net	9,799,000	10,455,000
Depreciation and amortization expense	2,600,000	2,300,000	2,200,000
Software and other intangible assets	984,000	416,000
Technical equipment and computers
Property and Equipment
Property and equipment, at cost	8,158,000	7,093,000
Technical equipment and computers | Minimum
Property and Equipment
Depreciable Life	3 years
Technical equipment and computers | Maximum
Property and Equipment
Depreciable Life	5 years
Leased assets
Property and Equipment
Property and equipment, at cost	17,451,000	17,700,000
Leased assets | Minimum
Property and Equipment
Depreciable Life	3 years
Leased assets | Maximum
Property and Equipment
Depreciable Life	15 years
Furniture, fixtures and equipment
Property and Equipment
Property and equipment, at cost	832,000	788,000
Depreciable Life	5 years
Leasehold improvements
Property and Equipment
Property and equipment, at cost	857,000	530,000
Leasehold improvements | Minimum
Property and Equipment
Depreciable Life	3 years
Leasehold improvements | Maximum
Property and Equipment
Depreciable Life	7 years
Construction-in-progress
Property and Equipment
Property and equipment, at cost	$ 583,000	$ 187,000