STOCKHOLDERS' EQUITY (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended							3 Months Ended				9 Months Ended		12 Months Ended	3 Months Ended							3 Months Ended				4 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
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 2005 Stock Plan	Jun. 30, 2011 2005 Stock Plan	May 18, 2011 2005 Stock Plan	Mar. 31, 2011 2005 Stock Plan	Dec. 31, 2010 2005 Stock Plan	Sep. 30, 2011 Stock Options	Jun. 30, 2011 Stock Options	Mar. 31, 2011 Stock Options	Sep. 30, 2010 Stock Options	Sep. 30, 2011 Stock Options Y	Sep. 30, 2010 Stock Options	Dec. 31, 2010 Stock Options	Sep. 30, 2011 Stock Options Low End of Range	Jun. 30, 2011 Stock Options Low End of Range	Mar. 31, 2011 Stock Options Low End of Range	Sep. 30, 2011 Stock Options High End of Range	Jun. 30, 2011 Stock Options High End of Range	Mar. 31, 2011 Stock Options High End of Range	Sep. 30, 2011 Restricted Stock Units and Performance-Based Restricted Stock Units	Sep. 30, 2011 Restricted Stock Units	Jun. 30, 2011 Restricted Stock Units	Mar. 31, 2011 Restricted Stock Units	Sep. 30, 2010 Restricted Stock Units	Sep. 30, 2011 Restricted Stock Units	Sep. 30, 2011 Restricted Stock Units Y	Sep. 30, 2010 Restricted Stock Units	Jun. 30, 2011 Performance-Based Restricted Stock Units	Mar. 31, 2011 Performance-Based Restricted Stock Units	Sep. 30, 2010 Performance-Based Restricted Stock Units	Sep. 30, 2011 Performance-Based Restricted Stock Units	Sep. 30, 2010 Performance-Based Restricted Stock Units	Sep. 30, 2011 2011 Plan Period	Jun. 30, 2011 2011 Plan	Mar. 31, 2011 2011 Plan	Sep. 30, 2011 2011 Plan Period	Sep. 30, 2011 Company ESPPs Y	Sep. 30, 2010 Company ESPPs Y	Sep. 30, 2011 Company ESPPs Y	Sep. 30, 2010 Company ESPPs Y	Sep. 30, 2011 1991 Employee Stock Purchase Plan	Mar. 31, 2011 1991 Employee Stock Purchase Plan	Sep. 30, 2010 1991 Employee Stock Purchase Plan	Sep. 30, 2011 1991 Employee Stock Purchase Plan	Sep. 30, 2010 1991 Employee Stock Purchase Plan	Sep. 30, 2011 2010 Employee Stock Purchase Plan	Dec. 31, 2010 2010 Employee Stock Purchase Plan
Share-based awards
Shares authorized for issuance					133,000,000																																													25,000,000
Generally, vesting period of options (in years)														four years
Generally, expiration period of options (in years)														ten years
Available for grant
Balance at the beginning of the period (in shares)					18,448,000	23,639,000		10,597,000	11,463,000
Additional shares authorized						19,000,000
Stock units issued (in shares)																								(3,874,000)	(461,000)	(642,000)					(3,409,000)	(9,000)					(3,409,000)	(9,000)
Adjustment for performance-based restricted stock units issued (in shares)																								(2,363,000)	(332,000)	(501,000)					(2,079,000)	(7,000)
Stock units cancelled (in shares)																								526,000	172,000	152,000
Adjustment for restricted stock units cancelled (in shares)																								410,000	134,000	119,000
Options cancelled/expired/forfeited (in shares)										111,000	17,000	22,000
Balance at the end of the period (in shares)					18,448,000	23,639,000		10,597,000	11,463,000																																								24,321,000
Outstanding Options, Number of Options
Balance at the beginning of the period (in shares)										9,146,000	10,171,000	12,660,000		12,660,000
Options cancelled/expired/forfeited (in shares)										(111,000)	(17,000)	(22,000)
Options exercised (in shares)										(313,000)	(1,008,000)	(2,467,000)
Balance at the end of the period (in shares)										8,722,000	9,146,000	10,171,000		8,722,000		12,660,000
Outstanding Options, Exercise Price per Share
Balance at the beginning of the period, low end of range (in dollars per share)										$ 1.68	$ 1.68	$ 1.68				$ 1.68
Balance at the beginning of the period, high end of range (in dollars per share)										$ 10.01	$ 10.01	$ 13.77				$ 14.94
Options cancelled/expired/forfeited, range (in dollars per share)																	$ 2.11	$ 2.11	$ 3.59	$ 4.43	$ 4.92	$ 14.94
Options exercised, range (in dollars per share)																	$ 1.80	$ 1.80	$ 1.80	$ 8.83	$ 13.77	$ 13.77
Balance at the end of the period, low end of range (in dollars per share)										$ 1.68	$ 1.68	$ 1.68				$ 1.68
Balance at the end of the period, high end of range (in dollars per share)										$ 10.01	$ 10.01	$ 13.77				$ 14.94
Weighted-Average Exercise Price per Share
Balances at the beginning of the period (in dollars per share)										$ 4.28	$ 4.28	$ 4.35		$ 4.35
Options cancelled/expired/forfeited (in dollars per share)										$ 4.24	$ 3.58	$ 6.68
Options exercised (in dollars per share)										$ 4.72	$ 4.28	$ 4.61		$ 4.72
Balance at the end of the period (in dollars per share)										$ 4.27	$ 4.28	$ 4.28		$ 4.27		$ 4.35
Share-based payment award
Shares counted against the numerical limit for options available for grant on or after May 18, 2011						1.61
Shares counted against the numerical limit for options available for grant prior to May 18, 2011						1.61	1.78
Restricted stock units issued, net of cancellations (in shares)																												6,921,000
Reduction of shares available for grant due to issue of restricted stock units																												11,054,000
Restricted stock units vested (in shares)																								1,878,000			1,536,000		3,755,000	2,658,000	8,476,000
Restricted stock units withheld for taxes (in shares)																								838,000			688,000		1,542,000	1,064,000
Weighted-average fair value of vested restricted stock units (in dollars per share)																								$ 12.84			$ 5.77		$ 14.07	$ 5.49	$ 14
Total stock-based compensation expense, net of income taxes	$ 13,682	$ 13,249	$ 41,751	$ 44,871																													$ 4,429	$ 6,511	$ 20,624
Number of Performance Period																																				3			3
Performance period																																							one year
Cumulative performance period																																		three year					three year
Cumulative recognized stock-based compensation expense																																				3,652			4,276
Unearned stock-based compensation expense related to non-vested awards										6,252				6,252									179,186
Weighted-average period of recognition of unearned compensation expense of non-vested awards (in years)														1.74															2.95
Options granted (in shares)													60,000		299,000
Restricted stock units issued, net of units withheld for taxes (in shares)																															5,127,000
Employee Stock Purchase Plan
Purchase price of the entity's common stock expressed as percentage of fair market value																																												85.00%			85.00%
Offering period (in months)																																															6 months
Percentage of employee's eligible compensation as limitation on purchases																																												10.00%			10.00%
Shares purchased																																														980,000	835,000	2,028,000	679,000
Average purchase price per share (in dollars per share)																																														$ 4.05	$ 4.85	$ 3.65	$ 8.56
Shares expired																																													1,888,000
Shares authorized for issuance					133,000,000																																													25,000,000
Shares available for issuance					18,448,000	23,639,000		10,597,000	11,463,000																																								24,321,000
Assumptions used to estimate the fair value of the Company ESPPs shares
Risk-free interest rate (as a percent)																																								0.07%	0.19%	0.12%	0.18%
Expected life (in years)																																								0.50	0.50	0.50	0.50
Expected volatility (as a percent)																																								51.00%	48.00%	46.00%	45.00%
Weighted-average fair value of the rights to purchase shares (in dollars per share)																																								$ 2.23	$ 1.02	$ 2.70	$ 0.89
Cash proceeds from the issuance of shares																																												6,207		3,974	6,207	7,411
Common Stock Repurchase Program
Authorized funding amount under stock repurchase program			500,000
Shares of common stock repurchased	6,095,000		13,826,000
Average price of shares repurchased (in dollars per share)	$ 9.23		$ 12.23
Reduction in common stock and additional paid-in capital by stock repurchases	56,271		169,083
Remaining authorized amount available for stock repurchase			$ 241,934