STOCK PLANS AND SHARE-BASED COMPENSATION (Details) (USD $)	3 Months Ended					3 Months Ended					1 Months Ended	3 Months Ended			3 Months Ended		1 Months Ended	3 Months Ended	1 Months Ended	3 Months Ended
	Mar. 31, 2014 plans	Mar. 31, 2013	Mar. 31, 2014 2007 Equity Incentive Plan [Member]	Mar. 31, 2014 Directors Equity Compensation Program [Member]	Mar. 31, 2014 Maximum [Member]	Mar. 31, 2014 Employee Stock [Member] purchaseperiods	Mar. 31, 2013 Employee Stock [Member]	Mar. 31, 2014 Restricted Stock Units (RSUs) [Member]	Mar. 31, 2013 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2013 Restricted Stock Units (RSUs) [Member]	Jul. 31, 2012 Restricted Stock Units (RSUs) [Member] Directors Equity Compensation Program [Member]	Mar. 31, 2014 Performance Based Awards [Member]	Mar. 31, 2013 Performance Based Awards [Member]	Dec. 31, 2013 Performance Based Awards [Member]	Mar. 31, 2014 Stock Options [Member]	Mar. 31, 2013 Stock Options [Member]	Jul. 31, 2012 Stock Options [Member] Directors Equity Compensation Program [Member]	Mar. 31, 2014 Incentive Stock Options [Member] 2007 Equity Incentive Plan [Member]	Jul. 31, 2012 Stock Options and Restricted Stock Units (RSUs) [Member] Directors Equity Compensation Program [Member]	Mar. 31, 2014 Nonstatutory Stock Options [Member] 2007 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for future issuance					6,870,264
Exercise price of stock options as percentage of fair market value on date of grant, minimum																		100.00%		100.00%
Vesting period			48 months	3 years				4 years							4 years
Factor used to determine the number of options/units to be granted											$ 100,000						$ 100,000		$ 100,000
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%
Shares reserved for issuance						3,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Employee Shares Purchased for Award						2,646,861
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant						353,139
Allocated Share-based Compensation Expense	$ 3,915,000	$ 3,636,000				$ 300,000	$ 300,000	$ 2,600,000	$ 1,900,000			$ 500,000	$ 400,000		$ 500,000	$ 1,000,000
Number of stock-based compensation plans	2
Awards expiration period, maximum (in years)			10 years
Number of purchase period in each offering period						1
Duration of each purchase period in each offering period						6 months
Number of performance-based awards shares released as percentage of target number, minimum												0.00%
Number of performance-based awards shares released as percentage of target number, maximum												200.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period								46,000				83,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number								750,000		714,000		44,000		100,000