Income Taxes - Uncertain Tax Positions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Uncertain Tax Positions [Roll Forward]
Beginning of year	$ 19.0	$ 19.4	$ 19.0	$ 19.3
Increases related to prior-year tax positions		0.8	0.1	1.0
Decreases related to prior-year tax positions		(1.6)	(1.3)	(1.0)
Increases related to current-year tax positions		1.3	1.9	1.3
Settlements		0	(7.0)	(0.4)
Effect of the expiration of statutes of limitation		(1.2)	(1.6)	(1.2)
Increases (decreases) related to business combinations and dispositions		(0.7)	8.3	0
Foreign exchange differences and reclassification		(0.8)	0	0
End of year		17.2	19.4	19.0
Components Of Income Tax Expense Benefit Continuing Operations [Abstract]
Redcution to Deferred Tax Assets due health legislation	$ 13.7