Reserves for Discounts and Allowances (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Analysis of the amount of, and change in, reserves
Balance, as of December 31, 2012	$ 237.1
Current provisions relating to sales in current year	456.7
Adjustments relating to prior years	(3.8)
Payments/returns relating to sales in current year	(185.1)
Payments/returns relating to sales in prior years	(150.3)
Balance, as of June 30, 2013	354.6
Discounts [Member]
Analysis of the amount of, and change in, reserves
Balance, as of December 31, 2012	15.5
Current provisions relating to sales in current year	115.9
Adjustments relating to prior years	(0.7)
Payments/returns relating to sales in current year	(56.4)
Payments/returns relating to sales in prior years	(13.8)
Balance, as of June 30, 2013	60.5
Contractual Adjustments [Member]
Analysis of the amount of, and change in, reserves
Balance, as of December 31, 2012	194.8
Current provisions relating to sales in current year	331.0
Adjustments relating to prior years	(4.3)
Payments/returns relating to sales in current year	(128.7)
Payments/returns relating to sales in prior years	(127.4)
Balance, as of June 30, 2013	265.4
Returns [Member]
Analysis of the amount of, and change in, reserves
Balance, as of December 31, 2012	26.8
Current provisions relating to sales in current year	9.8
Adjustments relating to prior years	1.2
Payments/returns relating to sales in current year	0
Payments/returns relating to sales in prior years	(9.1)
Balance, as of June 30, 2013	$ 28.7