STOCK PLANS AND SHARE BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2012

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-based Compensation Expense [Table Text Block]

The following table summarizes the stock-based compensation expense recognized in accordance with ASC 718-10 for the three months ended March 31, 2012 and March 31, 2011 (in thousands).

	Three Months Ended
	March 31,
	2012		2011
Cost of revenues	$	245	$	239
Research and development	1,120		811
Sales and marketing	747		667
General and administrative	919		787
Total stock-based compensation expense	$	3,031	$	2,504

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]

The fair value of employees’ stock purchase rights under the Purchase Plan was estimated using the Black-Scholes model with the following weighted-average assumptions:

	Three Months Ended
	March 31,
	2012	2011
Risk-free interest rates	0.09%	0.17%
Expected volatility rates	48%	37%
Expected dividend yield	0.54%	0.51%
Expected term of purchase right (years)	0.5	0.5
Weighted-average estimated fair value of purchase rights	$10.42	$9.40

Summary of Option Activity Under the Plans [Table Text Block]

A summary of stock option activity under the Plans, excluding performance-based shares and restricted stock units, as of March 31, 2012, and changes during the three months then ended, is presented below:

	Shares (in thousands)		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2012	3,557		$	24.01
Granted	—		—
Exercised	(215	)	19.58
Forfeited or expired	(3	)	21.09
Outstanding at March 31, 2012	3,339		$	24.29	4.52	$	43,032
Exercisable at March 31, 2012	2,866		$	23.44	3.96	$	39,249
Vested and expected to vest at March 31, 2012	3,322		$	24.24	4.50	$	42,986

Summary of Performance-based Awards Activity [Table Text Block]

A summary of performance-based awards outstanding as of March 31, 2012, and activity during the three months then ended, is presented below:

	Shares (in thousands)	Weighted- Average Grant Date Fair Value Per Share		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2012	—	$	—
Granted	96	37.28
Vested	—	—
Forfeited or expired	—	—
Outstanding at March 31, 2012	96	$	37.28	0.75	$	3,556
Vested and expected to vest at March 31, 2012	92			0.75	$	3,409

Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]

A summary of RSUs outstanding as of March 31, 2012, and changes during the three months then ended, is as follows:

	Shares (in thousands)		Weighted- Average Grant Date Fair Value Per Share		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2012	458		$	36.08
Granted	3		35.12
Vested	(5	)	37.23
Forfeited or expired	(6	)	37.09
Outstanding at March 31, 2012	450		$	36.04	1.38	$	16,708
Outstanding and expected to vest at March 31, 2012	420				1.37	$	15,596