Other Intangible Assets, Net (Roll Forward) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Other Intangible Assets Roll Forward
As at January 1,	$ 2,388.1	$ 2,493.0
Acquisitions	328.5	22.0
Amortization charged	(45.9)	(45.8)
Foreign currency translation	(13.5)	19.8
As at March 31,	$ 2,657.2	$ 2,489.0