Basis of Presentation - Income Taxes and Noncontrolling Interest (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Provision for/(benefit from) income taxes	$ 111.0	$ (329.0)	$ 544.0	$ (218.0)	$ (439.0)
Effective tax rate (as a percent)		(23.10%)		(5.60%)
Discrete tax benefits (charges)	170.0	$ (99.0)
Other (income) and expense
Noncontrolling interest amounts, net of tax	$ 3.5		$ 3.0	$ 7.1	$ 4.4
Accounting Standards Update 2016-16, Intra-Entity Transfers of Assets Other Than Inventory | Early adoption
Provision for/(benefit from) income taxes		$ (582.0)		$ (582.0)