NET INCOME PER SHARE (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Reconciliation of the numerator and denominator of basic and diluted net income (loss) per share
Net income	$ 20,387	$ 74,553
Weighted-average shares - basic	440,265	456,489
Incremental shares and share equivalents	4,662	13,533
Weighted-average shares - diluted	444,927	470,022
Basic
Net income per share (in dollars per share)	$ 0.05	$ 0.16
Diluted
Net income per share (in dollars per share)	$ 0.05	$ 0.16
Anti-dilutive securities not included in the "Weighted-average shares - diluted" used for calculation of diluted net income per share
Employee stock options and restricted stock units outstanding (in shares)	2,842	1,072