STOCK-BASED COMPENSATION (Details 2) (Stock options, USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				12 Months Ended
	Dec. 31, 2011 Y	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011 Y	Dec. 31, 2011 Y	Dec. 31, 2010 Y	Dec. 31, 2009 Y
Stock options
Weighted-average assumptions used to estimate the fair value of options granted
Dividend yield (as a percent)					0.00%	0.00%	0.00%
Expected volatility (as a percent)					53.60%	58.20%	62.80%
Risk-free interest rate (as a percent)					1.50%	1.90%	2.50%
Expected term (in years)					5.8	5.9	6.4
Stock Options, Number of Shares
Balance at the beginning of the period (in shares)				19,498,000	19,498,000
Granted (in shares)	95,000	110,000	103,000	118,000
Exercised (in shares)					(1,178,000)
Cancelled or forfeited (in shares)					(177,000)
Balance at the end of the period (in shares)	18,569,000				18,569,000	19,498,000
Vested and expected to vest in the future at the end of the period (in shares)	17,947,000				17,947,000
Exercisable at the end of the period (in shares)	14,366,000				14,366,000
Stock options, Weighted-Average Exercise Price Per Share
Balance at the beginning of the period (in dollars per share)				$ 8.59	$ 8.59
Granted (in dollars per shares)	$ 44.81	$ 40.45	$ 35.00	$ 28.81	$ 44.81
Exercised (in dollars per share)	$ 17.26				$ 17.26
Cancelled or forfeited (in dollars per share)					$ 21.25
Balance at the end of the period (in dollars per share)	$ 8.57				$ 8.57	$ 8.59
Vested and expected to vest in the future at the end of the period (in dollars per share)	$ 8.12				$ 8.12
Exercisable at the end of the period (in dollars per share)	$ 5.17				$ 5.17
Weighted-Average Remaining Contractual Term
Balance at the beginning of the period (in years)				5.2	5.2
Balance at the end of the period (in years)	4.1				4.1	5.2
Vested and expected to vest in the future at the end of the period (in years)					4.0
Exercisable at the end of the period (in years)					3.1
Aggregate Intrinsic Value
Balance at the beginning of the period				$ 342,241	$ 342,241
Balance at the end of the period	696,371				696,371	342,241
Vested and expected to vest in the future at the end of the period	681,183				681,183
Exercisable at the end of the period	$ 587,578				$ 587,578