STOCKHOLDERS' EQUITY (Details 5) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Common Stock Repurchase Program
Authorized amount under stock repurchase program	$ 500.0
Shares of common stock repurchased	9,500,000	5,700,000
Average price of shares repurchased (in dollars per share)	$ 10.18	$ 14.93
Reduction in common stock and additional paid-in capital by stock repurchases, excluding commission	96.2	85.1
Remaining authorized amount available for stock repurchase	10.6
Company ESPP
Assumptions used to estimate the fair value of the Company ESPPs shares
Risk-free interest rate (as a percent)	0.15%	0.17%
Expected life (in years)	0.50	0.50
Expected volatility (as a percent)	56.00%	41.00%
Weighted-average fair value of the rights to purchase shares (in dollars per share)	$ 2.27	$ 3.16
Cash proceeds from the issuance of shares	$ 5.4	$ 4.1
1991 Employee Stock Purchase Plan
Employee Stock Purchase Plan
Purchase price of the entity's common stock expressed as percentage of fair market value at the commencement or end of the offering peroid	85.00%
Offering period (in months)	P6M
Percentage of employee's eligible compensation as limitation on purchases	10.00%
Shares purchased		800,000
Average purchase price per share		$ 4.85
Number of shares available under the plan which have expired in the period		1,900,000
2010 Employee Stock Purchase Plan
Employee Stock Purchase Plan
Shares purchased	700,000
Average purchase price per share	$ 8.33
Shares authorized for issuance	25,000,000
Number of shares available for issuances	23,600,000