STOCK PLANS AND SHARE-BASED COMPENSATION (Details) (USD $)	1 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended	3 Months Ended		9 Months Ended					1 Months Ended	9 Months Ended	1 Months Ended		9 Months Ended
	Jun. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 plans	Sep. 30, 2012 Stock Options [Member]	Sep. 30, 2011 Stock Options [Member]	Sep. 30, 2012 Stock Options [Member]	Sep. 30, 2011 Stock Options [Member]	Sep. 30, 2012 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2011 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2011 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 1997 Employees Stock Purchase Plan [Member]	Sep. 30, 2011 1997 Employees Stock Purchase Plan [Member]	Sep. 30, 2012 1997 Employees Stock Purchase Plan [Member] purchaseperiods	Sep. 30, 2011 1997 Employees Stock Purchase Plan [Member]	Sep. 30, 2012 Performance-based Awards [Member]	Sep. 30, 2011 Performance-based Awards [Member]	Sep. 30, 2012 Performance-based Awards [Member]	Sep. 30, 2012 Employee Stock Options [Member]	Sep. 30, 2011 Employee Stock Options [Member]	Sep. 30, 2012 Employee Stock Options [Member]	Sep. 30, 2011 Employee Stock Options [Member]	Sep. 30, 2012 2007 Equity Incentive Plan [Member]	Sep. 30, 2012 2007 Equity Incentive Plan [Member] Incentive Stock Options [Member]	Sep. 30, 2012 2007 Equity Incentive Plan [Member] Nonstatutory Stock Options [Member]	Jul. 31, 2012 Directors Equity Compensation Program [Member]	Sep. 30, 2012 Directors Equity Compensation Program [Member]	Jul. 31, 2012 Directors Equity Compensation Program [Member] Stock Options [Member]	Jul. 31, 2012 Directors Equity Compensation Program [Member] Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 Minimum [Member] 1997 Employees Stock Purchase Plan [Member]	Sep. 30, 2011 Minimum [Member] 1997 Employees Stock Purchase Plan [Member]	Sep. 30, 2012 Minimum [Member] Employee Stock Options [Member]	Sep. 30, 2011 Minimum [Member] Employee Stock Options [Member]	Sep. 30, 2012 Maximum [Member] 1997 Employees Stock Purchase Plan [Member]	Sep. 30, 2011 Maximum [Member] 1997 Employees Stock Purchase Plan [Member]	Sep. 30, 2012 Maximum [Member] Employee Stock Options [Member]	Sep. 30, 2011 Maximum [Member] Employee Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional Shares Authorized	2,800,000
Number of shares available for future issuance			8,679,502									529,310		529,310
Vesting period						4 years				4 years													48 months				3 years
Exercise price of stock options as percentage of fair market value on date of grant, minimum																								100.00%	100.00%
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
Stock compensation expense		$ (700,000)		$ 1,100,000	$ 1,000,000	$ 3,000,000	$ 3,100,000	$ 2,000,000	$ 1,100,000	$ 5,100,000	$ 2,500,000	$ 300,000	$ 300,000	$ 800,000	$ 900,000	$ 400,000	$ (700,000)	$ 1,600,000								$ 100,000
Factor used to determine the number of options/units to be purchased																												$ 100,000	$ 100,000
Maximum percentage of employee's compensation eligible for payroll deductions												15.00%		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		3,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Employee Shares Purchased for Award												2,470,690		2,470,690
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%
Risk-free interest rates												0.14%	0.16%						0.87%	1.46%										0.09%	0.16%	0.87%	1.46%	0.14%	0.17%	1.01%	2.20%
Expected dividend yield												0.57%	0.59%						0.57%	0.59%										0.54%	0.51%	0.51%	0.54%	0.57%	0.59%	0.57%	0.59%
Expected volatility rates												34.00%	37.00%		37.00%				45.00%	44.00%	45.00%	44.00%								34.00%				48.00%