LONG-TERM DEBT (Details) (USD $)	1 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended			6 Months Ended
	Aug. 31, 2008	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011 2.0% convertible senior subordinated notes due June 1, 2015	Dec. 31, 2010 2.0% convertible senior subordinated notes due June 1, 2015	Jun. 30, 2010 2.0% convertible senior subordinated notes due June 1, 2015	Jun. 30, 2011 2.5% convertible senior subordinated notes due May 1, 2014	Dec. 31, 2010 2.5% convertible senior subordinated notes due May 1, 2014	Jun. 30, 2010 2.5% convertible senior subordinated notes due May 1, 2014	Jun. 30, 2011 Other	Dec. 31, 2010 Other
Long-term debt
Total debt		$ 1,078,087,000	$ 1,043,413,000	$ 819,990,000	$ 820,000,000		$ 500,000,000	$ 500,000,000		$ 8,708,000	$ 4,953,000
Less current portion		(672,102,000)	(651,997,000)
Total long-term debt		405,985,000	391,416,000
Debt discount				(153,600,000)	(170,183,000)		(97,011,000)	(111,357,000)
Interest rate (as a percent)				2.00%	2.00%	2.00%	2.50%	2.50%	2.50%
Percentage of principal amount at which the entity may redeem some or all of the debt instruments (as a percent)							100.00%
Conversion rate (as a percent)				20.00%			2.50%
Number of shares of the equity security into which debt will be converted (in shares)				21.4133			14.4928
Principal amount used for debt instrument conversion ratio				1,000			1,000
Short-term debt related to a variable interest entity for which the entity is the primary beneficiary		3,600,000
Stock price (in dollars per share)		$ 79.90	$ 61.72
Revolving credit facility with JP Morgan Chase Bank, N.A. and certain other lenders	$ 200,000,000
Term of revolving credit facility (in years)	3