PROPERTY AND EQUIPMENT (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property and equipment
Property and equipment, gross	$ 134,174,000	$ 103,072,000
Less: accumulated depreciation	(82,930,000)	(72,611,000)
Total property and equipment, net	51,244,000	30,461,000
Depreciation	12,500,000	15,600,000	19,300,000
Controller placements
Property and equipment
Property and equipment, gross	45,094,000	40,995,000
Less: accumulated depreciation	(25,700,000)
Computer equipment and software
Property and equipment
Property and equipment, gross	27,439,000	26,485,000
Machinery and equipment
Property and equipment
Property and equipment, gross	26,036,000	20,867,000
Furniture, fixtures and leasehold improvements
Property and equipment
Property and equipment, gross	8,738,000	5,531,000
Building and improvements
Property and equipment
Property and equipment, gross	7,614,000	7,280,000
Land
Property and equipment
Property and equipment, gross	5,738,000	745,000
Construction in process
Property and equipment
Property and equipment, gross	$ 13,515,000	$ 1,169,000