Fair Value Measurement (Financial Assets and Liabilities Not Measured on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capital lease obligation	$ 349.1
Carrying amount | Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capital lease obligation	349.1	$ 353.6
Fair value | Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capital lease obligation	349.1	353.6
Baxalta notes | Carrying amount | Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	5,065.2	5,063.6
Baxalta notes | Fair value | Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	5,294.1	5,066.5
SAIIDAC notes | Carrying amount | Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	12,047.7	12,039.2
SAIIDAC notes | Fair value | Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	$ 12,052.8	$ 11,633.8