Derivative Instruments And Hedging Activities (Narrative) (Details)	3 Months Ended		9 Months Ended				3 Months Ended	9 Months Ended										3 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended		9 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2011 USD ($)	Sep. 30, 2010 USD ($)	Sep. 30, 2011 USD ($)	Sep. 30, 2010 USD ($)	Sep. 30, 2011	Dec. 31, 2010 USD ($)	Sep. 30, 2010 Increase [Member] Provisional Pricing Arrangements [Member] Product Revenues [Member] USD ($)	Sep. 30, 2011 Minimum [Member] Twelve Month [Member]	Sep. 30, 2011 Maximum [Member] Twelve Month [Member]	Sep. 30, 2011 Twenty Four Month [Member]	Sep. 30, 2011 Fifteen Month [Member]	Sep. 30, 2011 Accounts Receivable [Member] USD ($)	Sep. 30, 2011 Derivative Assets (Current) [Member] Customer Supply Agreements [Member] USD ($)	Dec. 31, 2010 Derivative Assets (Current) [Member] Customer Supply Agreements [Member] USD ($)	Sep. 30, 2011 Foreign Exchange Contracts [Member] USD ($)	Dec. 31, 2010 Foreign Exchange Contracts [Member] USD ($)	Sep. 30, 2010 Foreign Exchange Contracts [Member]	Sep. 30, 2011 Foreign Exchange Contracts (Hedge Designation) [Member] USD ($)	Sep. 30, 2011 Foreign Exchange Contracts (Hedge Designation) [Member] USD ($)	Jan. 11, 2011 Foreign Exchange Contracts (Hedge Designation) [Member] CAD	Sep. 30, 2011 Provisional Pricing Arrangements [Member] USD ($)	Sep. 30, 2011 Provisional Pricing Arrangements [Member] USD ($)	Sep. 30, 2010 Provisional Pricing Arrangements [Member] Product Revenues [Member] USD ($)	Sep. 30, 2011 Changes In Fair Value Of Foreign Currency Contracts [Member] USD ($)	Sep. 30, 2011 Changes In Fair Value Of Foreign Currency Contracts [Member] USD ($)	Sep. 30, 2011 Accumulated Other Comprehensive Income [Member]	Sep. 30, 2010 Customer Supply Agreements [Member] USD ($)	Sep. 30, 2011 Customer Supply Agreements [Member] Product Revenues [Member] USD ($)	Sep. 30, 2010 Customer Supply Agreements [Member] Product Revenues [Member] USD ($)	Sep. 30, 2011 Customer Supply Agreements [Member] Product Revenues [Member] USD ($)	Sep. 30, 2010 Customer Supply Agreements [Member] Product Revenues [Member] USD ($)	Sep. 30, 2011 Product Revenues [Member] USD ($)	Sep. 30, 2010 Product Revenues [Member] USD ($)	Sep. 30, 2011 Product Revenues [Member] USD ($)	Sep. 30, 2010 Product Revenues [Member] USD ($)	Sep. 30, 2011 Pricing Settlement [Member] USD ($)
Percentage of hedging policy allowed anticipated operating cost								40.00%	75.00%	50.00%	10.00%
Notional amount of derivative																				4,700,000,000
Gains remain in accumulated other comprehensive loss related to the effective cash flow hedge contracts prior to de-designation																		15,200,000	10,300,000
Derivative instruments not designated as hedging instruments, gain (loss), net	240,600,000	290,100,000	849,900,000	1,087,700,000																	193,000,000	623,500,000						53,800,000	25,100,000	124,900,000	93,400,000					309,400,000
Foreign currency cash flow hedge gains to be reclassified to changes in fair value of foreign currency contracts during the next twelve months			10,300,000
Notional amounts of outstanding exchange rate contracts															45,000,000	230,000,000
Amount of gain/(loss) recognized in income on derivative		(32,500,000)		(24,800,000)			229,200,000																960,700,000	6,200,000	7,400,000		455,700,000					53,800,000	25,100,000	124,900,000	93,400,000
Notional amount of hedged portion of purchase price	315,000,000		315,000,000			70,000,000
Derivative asset, fair value												49,000,000
Fair value of derivative assets	116,800,000		116,800,000			45,600,000							67,800,000	45,600,000
Derivative assets	73,600,000		73,600,000			82,600,000
Swap resulted in net realized gains			93,100,000
Foreign currency spot rate					0.9700												0.97									0.9700
Reclassified gains from accumulated other comprehensive loss related to contracts that settled during the year, recorded the amounts as product revenues																																$ 1,800,000		$ 4,000,000