Debt (Details)			3 Months Ended			3 Months Ended			9 Months Ended												3 Months Ended						3 Months Ended
	Sep. 30, 2012 USD ($)	Dec. 31, 2011 USD ($)	Jun. 30, 2012 Revolving credit facility, due 2017 [Member] USD ($)	Sep. 30, 2012 Revolving credit facility, due 2017 [Member] USD ($)	Dec. 31, 2011 Revolving credit facility, due 2017 [Member] USD ($)	Jun. 30, 2012 Revolving Credit Facility, due 2014 [Member] USD ($)	Sep. 30, 2012 Revolving Credit Facility, due 2014 [Member] USD ($)	Dec. 31, 2011 Revolving Credit Facility, due 2014 [Member] USD ($)	Sep. 30, 2012 Senior Notes [Member] USD ($)	Sep. 30, 2012 Senior Notes [Member] Senior A Notes, Due 2022 [Member] USD ($)	Dec. 31, 2011 Senior Notes [Member] Senior A Notes, Due 2022 [Member] USD ($)	Sep. 30, 2012 Senior Notes [Member] Senior B Notes, Due 2024 [Member] USD ($)	Dec. 31, 2011 Senior Notes [Member] Senior B Notes, Due 2024 [Member] USD ($)	Sep. 30, 2012 Senior Notes [Member] Senior C Notes, Due 2027 [Member] USD ($)	Dec. 31, 2011 Senior Notes [Member] Senior C Notes, Due 2027 [Member] USD ($)	Sep. 30, 2012 Series A Floating Rate Notes Due 2012 [Member] USD ($)	Jul. 30, 2012 Series A Floating Rate Notes Due 2012 [Member] USD ($)	Dec. 31, 2011 Series A Floating Rate Notes Due 2012 [Member] USD ($)	Sep. 30, 2012 Series B Floating Rate Notes Due 2015 [Member] USD ($)	Dec. 31, 2011 Series B Floating Rate Notes Due 2015 [Member] USD ($)	Mar. 31, 2012 EURO Note A Due 2013 [Member]	Sep. 30, 2012 EURO Note A Due 2013 [Member] USD ($)	Sep. 30, 2012 EURO Note A Due 2013 [Member] EUR (€)	Dec. 31, 2011 EURO Note A Due 2013 [Member] USD ($)	Sep. 30, 2012 EURO Note B Due 2016 [Member] USD ($)	Dec. 31, 2011 EURO Note B Due 2016 [Member] USD ($)	Jun. 30, 2012 Convertible Debt Due 2047 [Member] USD ($)	Sep. 30, 2012 Convertible Debt Due 2047 [Member] USD ($)	Dec. 31, 2011 Convertible Debt Due 2047 [Member] USD ($)	Sep. 30, 2012 Term Loan Due 2014 [Member] USD ($)	Dec. 31, 2011 Term Loan Due 2014 [Member] USD ($)	Sep. 30, 2012 Capital leases, due through 2016 [Member] USD ($)	Dec. 31, 2011 Capital leases, due through 2016 [Member] USD ($)
Debt Instrument [Line Items]
Long-term debt	$ 401,400,000	$ 349,400,000		$ 99,400,000	$ 0		$ 0	$ 6,400,000	$ 168,000,000	$ 42,000,000	$ 0	$ 53,000,000	$ 0	$ 73,000,000	$ 0	$ 0	$ 50,000,000	$ 50,000,000	$ 25,000,000	$ 25,000,000		$ 26,300,000	€ 20,400,000	$ 26,300,000	$ 78,700,000	$ 79,000,000	$ 3,100,000	$ 3,100,000	$ 161,500,000	$ 200,000	$ 200,000
Capital leases																																700,000	1,000,000
Notes payable and other current debt	39,300,000	50,100,000
Long-term debt, excluding current portion	362,100,000	299,300,000
Expected period for Euro note A to be funded																					12 months
Line of credit facility, current borrowing capacity			300,000,000			225,000,000
Expiration date of credit facility			Apr. 30, 2017			Jun. 30, 2014
Line of credit facility, maximum capacity			350,000,000
Credit facility is available for swing-line loans			30,000,000
Credit available for the issuance of letters of credit			30,000,000
Line of credit interest rate margin added to Libor at minimum (in hundredths)			1.25%
Line of credit interest rate margin added to Libor at maximum (in hundredths)			2.25%
Debt Issuance Cost			1,600,000			800,000			1,200,000
Line of credit facility classified as short-term				13,000,000
Line of credit facility, classified as long-term				86,400,000
Aggregate principal amount repurchased																											158,400,000
Interest rate (in hundredths)										3.67%		3.82%		4.02%													4.00%
Approximately aggregate outstanding principal amount (in hundredth)																											98.06%
Convertible debt, purchase price per $1000 of debt																											1,038.91
Recognized a loss on debt extinguishment																											11,600,000
Purchase Premium Paid Convertible Debt																											6,200,000
Write off of Deferred Debt Issuance Cost																											4,400,000
Payments of Debt Extinguishment Costs																											$ 1,000,000
Weighted-average of the coupon interest rates on the Notes									3.87%
Annual effective rate of interest on the Notes, after interest-rate hedging and transaction costs									4.16%