Accumulated Other Comprehensive Income (Loss) (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other Comprehensive Income (Loss)
Net product sales	$ 1,644.0	$ 1,388.0	$ 4,637.4	$ 3,970.1
Interest (expense)	(24.0)	(17.9)	(61.5)	(40.7)
Income tax benefit (expense)	(69.5)	(52.3)	(212.7)	(198.1)
Interest and investment income, net	5.3	2.8	14.6	9.6
Net income	372.5	424.2	1,235.5	1,193.1
Gains (Losses) Reclassified Out of Accumulated Other Comprehensive Income
Other Comprehensive Income (Loss)
Net income	9.2	24.5	7.2	59.8
Gains (losses) from cash-flow hedges: | Gains (Losses) Reclassified Out of Accumulated Other Comprehensive Income
Other Comprehensive Income (Loss)
Income tax benefit (expense)	0.3	0.6	6.5	(2.4)
Gains (losses) from cash-flow hedges: | Gains (Losses) Reclassified Out of Accumulated Other Comprehensive Income | Foreign exchange contracts
Other Comprehensive Income (Loss)
Net product sales	12.0	24.8	7.6	62.8
Gains (losses) from cash-flow hedges: | Gains (Losses) Reclassified Out of Accumulated Other Comprehensive Income | Treasury rate lock agreements
Other Comprehensive Income (Loss)
Interest (expense)	(0.9)	(0.5)	(2.5)	(0.5)
Gains (losses) from available-for-sale marketable securities: | Gains (Losses) Reclassified Out of Accumulated Other Comprehensive Income
Other Comprehensive Income (Loss)
Income tax benefit (expense)	0.8	0	1.8	0
Interest and investment income, net	$ (3.0)	$ (0.4)	$ (6.2)	$ (0.1)