STOCK PLANS AND SHARE BASED COMPENSATION (Stock-Based Compensation) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 1,668,000	$ 2,935,000	$ 6,617,000	$ 7,477,000
Stock compensation expense	1,700,000	2,900,000	6,600,000	7,500,000
Compensation expense amortized from beginning inventory		(100,000)	(100,000)	(100,000)
Stock Options [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Unrecognized compensation costs	6,700,000		6,700,000
Unrecognized compensation costs, period of recognition (in years)			2
Stock compensation expense	1,000,000	1,300,000	3,100,000	4,000,000
Performance-based Awards [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock compensation expense	(700,000)	1,000,000		2,022,000
Restricted Stock Units (RSUs) [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Unrecognized compensation costs	11,700,000		11,700,000
Unrecognized compensation costs, period of recognition (in years)			3.2
Stock compensation expense	1,100,000	500,000	2,500,000	834,000
Employees Stock Purchase Plan [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Unrecognized compensation costs	400,000		400,000
Unrecognized compensation costs, period of recognition (in years)			0.5
Stock compensation expense	300,000	232,000	900,000	777,000
Cost of revenues [Member]
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	128,000	153,000	584,000	481,000
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	564,000	1,125,000	2,354,000	2,782,000
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	449,000	727,000	1,659,000	1,776,000
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	$ 527,000	$ 930,000	$ 2,020,000	$ 2,438,000