STOCK PLANS AND SHARE BASED COMPENSATION (Stock-Based Compensation) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 8,969,000	$ 10,721,000	$ 11,328,000
Compensation expense amortized from capitalized inventory	29,000	(100,000)	100,000
Cost of revenues [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	666,000	686,000	790,000
Research and Development Expense [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	3,274,000	4,107,000	4,371,000
Selling and Marketing Expense [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	2,313,000	2,594,000	2,548,000
General and Administrative Expense [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	2,716,000	3,334,000	3,619,000
Stock Options [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Unrecognized compensation costs	5,700,000
Unrecognized compensation costs, period of recognition (in years)	1.9
Compensation expense	4,000,000	5,200,000	6,900,000
Performance-based Awards [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Compensation expense	0	3,000,000	2,200,000
Restricted Stock Units (RSUs) [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Unrecognized compensation costs	11,900,000
Unrecognized compensation costs, period of recognition (in years)	2.8
Compensation expense	3,800,000	1,500,000
Employees Stock Purchase Plan [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Unrecognized compensation costs	100,000
Unrecognized compensation costs, period of recognition (in years)	0.5
Compensation expense	$ 1,200,000	$ 1,100,000	$ 2,100,000