Notes Payable and Long-Term Debt (Details) (USD $)	12 Months Ended											12 Months Ended					12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Total Short Term Debt [Member]	Dec. 31, 2011 Total Short Term Debt [Member]	Dec. 31, 2012 Short Term Borrowings [Member]	Dec. 31, 2011 Short Term Borrowings [Member]	Dec. 31, 2012 Receivables Securitization [Member]	Nov. 01, 2012 Receivables Securitization [Member]	Dec. 31, 2011 Receivables Securitization [Member]	Sep. 08, 2010 Receivables Securitization [Member]	Dec. 21, 2009 Receivables Securitization [Member]	Dec. 31, 2012 Convertible Senior Notes Due April 2012 [Member]	Dec. 31, 2011 Convertible Senior Notes Due April 2012 [Member]	Dec. 31, 2010 Convertible Senior Notes Due April 2012 [Member]	Apr. 09, 2009 Convertible Senior Notes Due April 2012 [Member]	Dec. 31, 2012 Senior Notes One [Member]	Dec. 31, 2012 Senior Notes Due November 2016 [Member]	Dec. 31, 2011 Senior Notes Due November 2016 [Member]	Dec. 31, 2012 Senior Notes Due October 2019 [Member]	Dec. 31, 2011 Senior Notes Due October 2019 [Member]	Dec. 31, 2012 Senior Notes Due September 2020 [Member]	Dec. 31, 2011 Senior Notes Due September 2020 [Member]	Dec. 31, 2012 Senior Notes Due February 2029 [Member]	Dec. 31, 2011 Senior Notes Due February 2029 [Member]	Dec. 31, 2012 Multi Currency Revolving Credit Facility [Member]	Dec. 31, 2011 Multi Currency Revolving Credit Facility [Member]	Dec. 31, 2012 Term Loan Facilities And Other [Member]	Dec. 31, 2011 Term Loan Facilities And Other [Member]	Dec. 31, 2012 Unamortized portion of debt derivative [Member]	Dec. 31, 2011 Unamortized portion of debt derivative [Member]
Short-term debt
Total short-term debt			$ 239,100,000	$ 196,300,000	$ 129,100,000	$ 116,300,000	$ 110,000,000	$ 110,000,000	$ 80,000,000	$ 80,000,000	$ 50,000,000
Long-term Debt, by Current and Noncurrent [Abstract]
Total long-term debt	828,100,000	1,132,800,000										0	368,500,000				149,600,000	149,500,000	133,900,000	133,900,000	247,900,000	247,700,000	119,400,000	119,300,000	140,000,000	70,000,000	17,100,000	19,800,000	20,200,000	24,100,000
Current portion of long-term debt	4,300,000	381,500,000
Long-term debt, net of current portion	823,800,000	751,300,000
Debt instrument par value															373,800,000		150,000,000		134,000,000		250,000,000		121,000,000
Debt instrument stated interest rate												3.50%					5.75%		8.00%		4.625%		7.125%
Debt instrument maturity period																	Nov. 01, 2016		Oct. 01, 2019		Sep. 15, 2020		Feb. 15, 2029
Weighted average interest rate	4.00%	5.90%
Long-term Debt, by Maturity [Abstract]
2013	243,400,000
2014	400,000
2015	12,400,000
2016	290,000,000
2017	0
After 2017	524,800,000
Total payments	1,071,000,000
Less: unamortized discounts	(3,800,000)
Total	1,067,200,000
Multi-currency revolving credit agreement, current borrowing capacity																									650,000,000
Multi-currency revolving credit agreement, maximum borrowing capacity																									1,000,000,000
Debt conversion, original debt, amount	373,800,000
Stock Issued During Period, Shares, Conversion of Convertible Securities	11,400,000
Conversion of convertible securities, value of shares issued	617,300,000
Adjustments to additional paid in capital, equity component of convertible debt	243,500,000
Interest expense												9,000,000	33,100,000	31,300,000
Non-cash portion												5,300,000	20,000,000	18,300,000
Bond hedge overlay at net pre-tax cost																25,200,000
Conversion premium after bond hedge overlay																50.00%
Conversion price per share after bond hedge overlay																$ 38.61
Treasury stock received from bond hedge, shares	6,500,000
Treasury stock received from bond hedge, value	503,900,000
Adjustments to additional paid in capital, bond hedge	503,900,000
Treasury stock issued due to settlement of warrant, shares	4,900,000
Treasury stock issue due to settlement of warrant, value	338,500,000
Adjustments to additional paid in capital, warrant	338,500,000
Estimated fair value of senior unsecured notes	770,300,000	1,454,400,000
Fair value higher than carrying value for senior unsecured notes	119,500,000	435,500,000
Outstanding letters of credit	$ 59,100,000	$ 58,500,000