STOCK PLANS AND SHARE-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2014

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, 2014, and March 31, 2013 (in thousands).

	Three Months Ended
	March 31,
	2014		2013
Cost of revenues	$	219	$	264
Research and development	1,212		1,106
Sales and marketing	935		829
General and administrative	1,549		1,437
Total stock-based compensation expense	$	3,915	$	3,636

Schedule of Unrecognized Compensation Expense for Unvested Awards [Table Text Block]

The following table summarizes total compensation expense related to unvested awards not yet recognized, net of expected forfeitures, and the weighted-average period over which it is expected to be recognized as of March 31, 2014.

	March 31, 2014
	Unrecognized Compensation Expense for Unvested Awards			Weighted Average Remaining Recognition Period
	(In thousands)			(In years)
Options		$	1,497		1.44
Performance-based awards		1,706			0.75
Long term performance-based awards		2,156			2.75
Restricted stock units		20,511			2.38
Purchase plan		396			0.50
Total unrecognized compensation expense		$	26,266

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,
	2014	2013
Risk-free interest rates	0.07%	0.11%
Expected volatility rates	30%	33%
Expected dividend yield	0.66%	0.80%
Expected term of purchase right (in years)	0.5	0.5
Weighted-average estimated fair value of purchase rights	$13.31	$9.14

Summary of Option Activity Under the Plans

A summary of stock option activity under the Plans, excluding performance-based awards and restricted stock units, as of March 31, 2014, 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, 2014	1,691		$27.34
Granted	—		—
Exercised	(176	)	$27.26
Forfeited or expired	—		—
Outstanding at March 31, 2014	1,515		$27.35	4.30	$	58,210
Exercisable at March 31, 2014	1,400		$26.29	4.03	$	55,288
Vested and expected to vest at March 31, 2014	1,512		$27.32	4.29	$	58,145

Performance Based Awards [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

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

A summary of performance-based awards outstanding as of March 31, 2014, 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, 2014	100		$38.48
Granted	44		$58.55
Vested	(83	)	$38.48
Change in units due to performance achievement for PSUs vested in the year	(17	)	$38.48
Forfeited or expired	—		—
Outstanding at March 31, 2014	44		$58.55	0.75	$	2,868
Outstanding and expected to vest at March 31, 2014	37			0.75	$	2,466

Long-Term Performance-based Awards [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

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

A summary of long-term performance-based awards outstanding as of March 31, 2014, 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, 2014	—	—
Granted	47	$57.76
Vested	—	—
Forfeited or expired	—	—
Outstanding at March 31, 2014	47	$57.76	2.75	$	3,072
Outstanding and expected to vest at March 31, 2014	40		2.75	$	2,629

Restricted Stock Units (RSUs) [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

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

A summary of RSUs outstanding as of March 31, 2014, and changes during the three months then ended, are 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, 2014	714		$38.97
Granted	86		$57.05
Vested	(46	)	$35.93
Forfeited or expired	(4	)	$39.47
Outstanding at March 31, 2014	750		$41.21	1.44	$	49,312
Outstanding and expected to vest at March 31, 2014	704			1.34	$	46,280