Accounts Receivable, Net (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Provision for discounts and doubtful accounts
As at January 1,	$ 31.1	$ 23.4
Provision charged to operations	214.9	172.5
Provision utilization	(196.5)	(169.0)
As at September 30,	49.5	26.9
Accounts receivable, net	863.6		845.0
Accounts receivable related to royalty income	41.1		73.3
Royalty receivable related to royalty income from 3TC & ZEFFIX	$ 38.0