STOCK PLANS AND SHARE BASED COMPENSATION (Details)	12 Months Ended
Dec. 31, 2011 plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plans	2
Common stock reserved for future issuance under stock option and stock purchase plans	3,000,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	4 years
1997 Employees Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of employee's compensation eligible for payroll deductions	15.00%
Purchase price of the purchase plan as percentage of the lower of the fair market value on the first day of each offering period or on the purchase date	85.00%
Number of purchase period in each offering period	1
Duration of each purchase period in each offering period	6 months
Shares reserved for issuance	3,000,000
Number of shares purchased	2,345,615
Number of shares available for future issuance	654,385
2007 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for future issuance	6,554,151
2007 Equity Incentive Plan [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	48 months
Awards expiration period, maximum	10 years
2007 Equity Incentive Plan [Member] \| Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of stock options as percentage of fair market value on date of grant, minimum	100.00%
2007 Equity Incentive Plan [Member] \| Nonstatutory Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of stock options as percentage of fair market value on date of grant, minimum	100.00%
Directors Equity Compensation Program [Member] \| Nonstatutory Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Multiplier for calculation of common stock options granted to directors on the first trading day of the month following commencement of service	8,000
Number of options granted to directors on the first trading day of July following commencement of service	24,000
Awards vesting period	3 years

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Exercise Price As Percentage Of Fair Market Value On Grant Date, Minimum

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Multiplier For Calculation Of Common Stock Options Granted To Directors Upon Commencement Of Service

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Number of Stock-based Compensation Plans

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Purchase Price as Percentage of Lower of Fair Market Value on First Day of Offering Period or Purchase Date.

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Share-based Compensation Arrangement by Share-based Payment Award, Award Expiration Period

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Aggregate number of common shares reserved for future issuance.

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Description of the period of time over which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, which may be expressed in a variety of ways (for example, in years, month and year).

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The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The number of shares purchased on the open market during the period for issuance to employees under the plan.

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