FINANCIAL INFORMATION Revised Consolidated Statements of Operations (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net revenues:
Products	$ 87,315	$ 99,858	$ 181,885	$ 198,576
Services	37,329	41,487	77,741	78,840
Total net revenues	124,644	141,345	259,626	277,416
Cost of revenues:
Products	35,097	38,902	70,091	75,917
Services	15,323	15,392	30,994	30,668
Amortization of intangible assets	0	501	50	1,152
Total cost of revenues	50,420	54,795	101,135	107,737
Gross profit	74,224	86,550	158,491	169,679
Operating expenses:
Research and development	22,070	23,847	45,024	47,454
Marketing and selling	34,297	33,903	67,112	67,812
General and administrative	19,984	16,131	38,315	31,728
Amortization of intangible assets	398	658	878	1,321
Restructuring (recoveries) costs, net	(165)	1,918	(165)	2,191
Loss on sale of assets			0	(125)
Total operating expenses	76,584	76,457	151,164	150,506
Operating loss	(2,360)	10,093	7,327	19,173
Interest income	50	122	70	195
Interest expense	(415)	(374)	(788)	(709)
Other income (expense), net	8	5	10	9
Loss before income taxes	(2,717)	9,846	6,619	18,668
Provision for income taxes, net	622	669	1,062	1,226
Net (loss) income	$ (3,339)	$ 9,177	$ 5,557	$ 17,442
Net loss per common share - basic	$ (0.09)	$ 0.24	$ 0.14	$ 0.45
Net loss per common share - diluted	$ (0.09)	$ 0.23	$ 0.14	$ 0.45
Weighted-average common shares outstanding - basic	39,119	39,040	39,109	39,009
Weighted-average common shares outstanding - diluted	39,119	39,069	39,138	39,061