Derivative Instruments and Hedging Activities (Details) (USD $)						1 Months Ended															1 Months Ended
	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2011 Designated as hedging instruments Foreign currency forward contracts	Dec. 31, 2010 Designated as hedging instruments Foreign currency forward contracts	Jun. 30, 2011 Designated as hedging instruments Interest rate swap contracts contracts	Aug. 31, 2011 Designated as hedging instruments Interest rate swap contracts 2.450% senior notes due 2015	Sep. 30, 2011 Foreign currency forward contracts	Dec. 31, 2010 Foreign currency forward contracts	Sep. 30, 2011 Foreign currency forward contracts Australian Dollar	Dec. 31, 2010 Foreign currency forward contracts Australian Dollar	Dec. 31, 2010 Foreign currency forward contracts British Pound	Sep. 30, 2011 Foreign currency forward contracts Canadian Dollar	Dec. 31, 2010 Foreign currency forward contracts Canadian Dollar	Sep. 30, 2011 Foreign currency forward contracts Euro	Dec. 31, 2010 Foreign currency forward contracts Euro	Sep. 30, 2011 Foreign currency forward contracts Japanese Yen	Dec. 31, 2010 Foreign currency forward contracts Japanese Yen	Sep. 30, 2011 Foreign currency forward contracts Swiss Franc	Dec. 31, 2010 Foreign currency forward contracts Swiss Franc	Dec. 31, 2010 Foreign currency forward contracts Others	Aug. 31, 2011 2.450% senior notes due 2015
Summary of Derivative Instruments
Period to settlement dates of derivatives is within this period (in months)			36 months	36 months
Notional amount							$ 1,607,150,000	$ 1,632,281,000	$ 14,280,000	$ 51,809,000	$ 58,440,000	$ 93,768,000	$ 133,128,000	$ 794,766,000	$ 675,438,000	$ 647,960,000	$ 632,962,000	$ 56,376,000	$ 77,669,000	$ 2,835,000
Aggregate notional amount of foreign currency forward non-designated hedging contracts	1,023,200,000	848,600,000
Number of interest rate swap contracts, designated as fair value hedges, held by the entity					3
Proceeds from settlement of interest rate swap contracts						$ 34,300,000															$ 34,300,000