Fair Value Measurement (Financial Assets and Liabilities Not Measured on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	$ 12,037.0	$ 0.0
Capital lease obligation	348.6
Fair value | Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	12,080.9	0.0
Capital lease obligation	348.6	13.4
Carrying value | Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	12,037.0	0.0
Capital lease obligation	348.6	13.4
Baxalta
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	5,104.4	0.0
Baxalta | Fair value | Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	5,467.7	0.0
Baxalta | Carrying value | Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	$ 5,104.4	$ 0.0