Financial Instruments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Minimum
Guarantor Obligations [Line Items]
Number of countries in which entity has currency exposures	50
Stand by letters of credit, bonds and bank guarantees
Guarantor Obligations [Line Items]
Contingent liability outstanding	$ 208.8	$ 273.6
Stand by letters of credit, bonds and bank guarantees | Minimum
Guarantor Obligations [Line Items]
Fees paid to various banks and insurance companies on face amount of instruments (as a percent)	0.32%
Stand by letters of credit, bonds and bank guarantees | Maximum
Guarantor Obligations [Line Items]
Guarantee term	5 years
Fees paid to various banks and insurance companies on face amount of instruments (as a percent)	1.93%
Guarantees of debt of certain third parties related to international operations
Guarantor Obligations [Line Items]
Service revenues	1.3	1.2	1.9
Potential amount of future payments for guarantees, maximum	0.7	1.6
Environmental indemnification for properties sold to third party in 2007 | Maximum
Guarantor Obligations [Line Items]
Guarantee term	20 years
Environmental indemnification for property from a lease terminated in 2006
Guarantor Obligations [Line Items]
Potential amount of future payments for guarantees, maximum	3.0
Guarantees related to arrangements with certain customers
Guarantor Obligations [Line Items]
Potential amount of future payments for guarantees per occurrence, maximum	$ 3.0
Guarantees related to arrangements with certain customers | Maximum
Guarantor Obligations [Line Items]
Guarantee term	4 years