Revenue Reserves (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Analysis of the amount of, and change in, reserves
Beginning balance	$ 155.6	$ 142.0	$ 103.1
Current provisions relating to sales in current year	652.7	472.1	381.7
Adjustments relating to prior years	(5.1)	(14.9)	(6.9)
Payments/returns relating to sales in current year	(451.1)	(350.7)	(253.8)
Payments/returns relating to sales in prior years	(115.0)	(92.9)	(82.1)
Ending balance	237.1	155.6	142.0
Discounts
Analysis of the amount of, and change in, reserves
Beginning balance	12.6	13.9	13.9
Current provisions relating to sales in current year	113.8	96.0	80.6
Adjustments relating to prior years	(0.3)	0	(2.7)
Payments/returns relating to sales in current year	(99.6)	(84.3)	(68.7)
Payments/returns relating to sales in prior years	(11.0)	(13.0)	(9.2)
Ending balance	15.5	12.6	13.9
Contractual Adjustments
Analysis of the amount of, and change in, reserves
Beginning balance	119.3	107.0	70.3
Current provisions relating to sales in current year	516.9	360.4	285.0
Adjustments relating to prior years	(4.7)	(14.0)	(2.4)
Payments/returns relating to sales in current year	(347.2)	(266.0)	(184.3)
Payments/returns relating to sales in prior years	(89.5)	(68.1)	(61.6)
Ending balance	194.8	119.3	107.0
Returns
Analysis of the amount of, and change in, reserves
Beginning balance	23.7	21.1	18.9
Current provisions relating to sales in current year	22.0	15.7	16.1
Adjustments relating to prior years	(0.1)	(0.9)	(1.8)
Payments/returns relating to sales in current year	(4.3)	(0.4)	(0.8)
Payments/returns relating to sales in prior years	(14.5)	(11.8)	(11.3)
Ending balance	$ 26.8	$ 23.7	$ 21.1