Accumulated Other Comprehensive Income (Loss) (Reclassification of AOCI) (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Other Comprehensive Income (Loss)    
Net product sales $ 2,055.2 $ 1,707.5
Interest (expense) (49.2) (29.3)
Income tax benefit (108.2) (52.6)
Interest and investment income, net 9.0 6.4
Net income 718.9 279.7
Gains (Losses) Reclassified Out of Accumulated Other Comprehensive Income    
Other Comprehensive Income (Loss)    
Net income 70.1 (2.5)
Gains (Losses) Reclassified Out of Accumulated Other Comprehensive Income | Gains (losses) from cash-flow hedges: | Foreign exchange contracts    
Other Comprehensive Income (Loss)    
Net product sales 70.5 (1.0)
Gains (Losses) Reclassified Out of Accumulated Other Comprehensive Income | Gains (losses) from cash-flow hedges: | Treasury rate lock agreements    
Other Comprehensive Income (Loss)    
Interest (expense) (0.9) (0.9)
Gains (Losses) Reclassified Out of Accumulated Other Comprehensive Income | Gains (losses) from cash-flow hedges: | Interest rate swap agreements    
Other Comprehensive Income (Loss)    
Interest (expense) (0.4) 0
Income tax benefit 0.5 0.3
Gains (Losses) Reclassified Out of Accumulated Other Comprehensive Income | Gains (losses) from available-for-sale marketable securities:    
Other Comprehensive Income (Loss)    
Income tax benefit (0.2) 0.5
Interest and investment income, net $ 0.6 $ (1.4)