Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2009	$ 3,878,810,000	$ 127,825,000	$ 2,269,905,000	$ 1,701,437,000	$ (205,017,000)	$ (15,340,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends, Common Stock, Cash	(12,839,000)	0	0	(12,839,000)	0	0
Stocks Acquired Issued For Benefit Plans	68,000	0	0	0	68,000	0
Stock Issued During Period Value Stock Options Exercised Net Of Amortization Forfeitures	12,539,000	386,000	12,153,000	0	0	0
Treasury Stock, Value, Acquired, Cost Method	(100,942,000)	0	0	0	(100,942,000)	0
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt	106,083,000	0	106,083,000	0	0	0
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	10,597,000	1,423,000	36,837,000	0	(27,663,000)	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(106,109,000)	0	0	(106,109,000)	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	30,554,000	0	0	0	0	30,554,000
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest CLONE at Dec. 31, 2010	3,818,761,000	129,634,000	2,424,978,000	1,582,489,000	(333,554,000)	15,214,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends, Common Stock, Cash	(17,217,000)	0	0	(17,217,000)	0	0
Stocks Acquired Issued For Benefit Plans	(14,000)	0	0	0	(14,000)	0
Stock Issued During Period Value Stock Options Exercised Net Of Amortization Forfeitures	42,010,000	1,565,000	40,466,000	0	(21,000)	0
Treasury Stock, Value, Acquired, Cost Method	(140,127,000)	0	0	0	(140,127,000)	0
Translation adjustment recorde as loss on sales of CRO	(2,210,000)	0	0	0	0	(2,210,000)
Stockholders' Equity, Other	(348,000)	0	0	(348,000)	0	0
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	13,629,000	558,000	23,497,000	(19,000)	(10,407,000)	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	86,924,000	0	0	86,924,000	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(5,972,000)	0	0	0	0	(5,972,000)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest CLONE at Dec. 31, 2011	3,795,436,000	131,757,000	2,488,941,000	1,651,829,000	(484,123,000)	7,032,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends, Common Stock, Cash	(45,214,000)	0	0	(45,214,000)	0	0
Stocks Acquired Issued For Benefit Plans	39,000	0	0	0	39,000	0
Stock Issued During Period Value Stock Options Exercised Net Of Amortization Forfeitures	51,156,000	1,295,000	50,093,000	0	(232,000)	0
Treasury Stock, Value, Acquired, Cost Method	(339,117,000)	0	0	0	(339,117,000)	0
Adjustments to Additional Paid in Capital; Equity Component of Capped Call Transaction	(48,126,000)	0	(48,126,000)	0	0	0
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt	(54,546,000)	0	(54,546,000)	0	0	0
Forward Contract Indexed to Issuer's Equity, Redeemable Stock, Redemption Requirements, Amount	(50,000,000)	0	(50,000,000)	0	0	0
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	11,062,000	451,000	33,608,000	(414,000)	(22,583,000)	0
Change in Equity: Translation Adjustment Relating to Divestiture of Business	(9,722,000)	0	0	0	0	(9,722,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	194,874,000	0	0	194,874,000	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(130,000)	0	0	0	0	(130,000)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest CLONE at Dec. 31, 2012	$ 3,505,712,000	$ 133,503,000	$ 2,419,970,000	$ 1,801,075,000	$ (846,016,000)	$ (2,820,000)