Income Taxes - Uncertain Tax Positions (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Uncertain Tax Positions [Roll Forward]
Beginning of year	$ 17.2	$ 19.4	$ 19.0
Increases related to prior-year tax positions	1.4	0.8	0.1
Decreases related to prior-year tax positions	(6.9)	(1.6)	(1.3)
Increases related to current-year tax positions	1.6	1.3	1.9
Settlements	(0.7)	0	(7.0)
Effect of the expiration of statutes of limitation	(1.2)	(1.2)	(1.6)
Increases (decreases) related to business combinations and dispositions	0	(0.7)	8.3
Foreign exchange differences and reclassification	0.4	(0.8)	0
End of year	$ 11.8	$ 17.2	$ 19.4