Other Non-current Liabilities (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Other Liabilities, Noncurrent [Abstract]
Income taxes payable	$ 88.9	$ 78.3
Deferred revenue	11.9	12.2
Deferred rent	12.2	14.0
Insurance provisions	13.8	14.5
Contingent consideration payable	117.4	0
Other non-current liabilities	27.3	25.3
Other noncurrent liabilities, total	$ 271.5	$ 144.3