Debt (Details) (USD $) In Millions, unless otherwise specified			6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011 Credit Agreement	Feb. 26, 2008 Credit Agreement	Feb. 26, 2008 Credit Agreement Prime or Federal Funds	Jun. 30, 2011 Credit Agreement LIBOR	Feb. 26, 2008 Credit Agreement LIBOR	Jun. 30, 2011 Credit Agreement Federal Funds	Jun. 30, 2011 US Dollar term loan under the Credit Agreement	Dec. 31, 2010 US Dollar term loan under the Credit Agreement	Feb. 26, 2008 US Dollar term loan under the Credit Agreement	Jun. 30, 2011 US Dollar revolving loans under the Credit Agreement	Dec. 31, 2010 US Dollar revolving loans under the Credit Agreement	Feb. 26, 2008 US Dollar revolving loans under the Credit Agreement	Jun. 30, 2011 Capital lease obligations	Dec. 31, 2010 Capital lease obligations	Jun. 30, 2011 Other revolving loans
Debt
Total long-term debt	$ 102.3	$ 115.5							$ 97.5	$ 110.6					$ 4.8	$ 4.9
Current portion of long-term debt	(42.1)	(28.9)
Total long-term debt, less current portion	60.2	86.6
Maximum commitment												250.0		230.0			173.0
Term facility											150.0
Interest rate added to base rate (as a percent)					0.50%	1.00%		0.50%
Interest rate added to base rate, low end of range (as a percent)						0.80%	0.40%
Interest rate added to base rate, high end of range (as a percent)						1.65%	1.25%
Facility fee, low end of range (as a percent)			0.20%	0.10%
Facility fee, high end of range (as a percent)			0.35%	0.20%
Weighted Average Interest Rate (as a percent)			2.70%									1.30%
Maximum leverage ratio			3.0
Minimum interest coverage ratio			3.0
Short-term borrowings
Total short-term borrowings	$ 185.5	$ 185.5										$ 185.5	$ 185.5