Financial Instruments (Details) (USD $) In Millions, unless otherwise specified				12 Months Ended									12 Months Ended
	Dec. 31, 2011 country	Dec. 31, 2011 Standby letters of credit, bonds and bank guarantees	Dec. 31, 2010 Standby letters of credit, bonds and bank guarantees	Dec. 31, 2011 Standby letters of credit, bonds and bank guarantees Minimum	Dec. 31, 2011 Standby letters of credit, bonds and bank guarantees Maximum	Dec. 31, 2011 Guarantees of debt of certain third parties related to international operations	Dec. 31, 2010 Guarantees of debt of certain third parties related to international operations	Dec. 31, 2009 Guarantees of debt of certain third parties related to international operations	Dec. 31, 2007 Environmental indemnification for properties sold to third party in 2007 Maximum	Dec. 31, 2011 Environmental indemnification for property from a lease terminated in 2006	Dec. 31, 2010 Environmental indemnification for property from a lease terminated in 2006	Dec. 31, 2011 Guarantees related to arrangements with certain customers	Dec. 31, 2011 Guarantees related to arrangements with certain customers Maximum
Financial Instruments
Number of countries in which entity has currency exposures, minimum	50
Third-party guarantees
Contingent liability outstanding		$ 273.6	$ 268.1
Service revenues						1.2	1.9	9.6
Guarantee term (in years)					P3Y				P20Y				P4Y
Fees paid to various banks and insurance companies on face amount of instruments (as a percent)				0.25%	2.30%
Potential amount of future payments for guarantees, maximum						1.6	1.6			3.0	3.0
Potential amount of future payments for guarantees per occurrence, maximum												$ 3.0