Other Intangible Assets, Net (Roll Forward) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other Intangible Assets Roll Forward
As at January 1,	$ 2,493.0	$ 1,978.9
Acquisitions	281.6	717.1
Amortization charged	(194.8)	(166.7)
Impairment charges	(197.9)	(16.0)	(42.7)
Foreign currency translation	6.2	(20.3)
As at December 31,	$ 2,388.1	$ 2,493.0	$ 1,978.9