Accounting Policies - Accumulated Other Comprehensive Loss by Component, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 9,993.6	$ 2,869.1
Other comprehensive income (loss) before reclassifications	(178.7)	(53.0)
Amounts reclassified from accumulated other comprehensive income	0.7	0.6
Net current period other comprehensive income (loss)	(178.0)	(52.4)
Ending Balance	9,797.7	9,780.4
Foreign currency translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(308.6)	(202.2)
Other comprehensive income (loss) before reclassifications	(181.4)	(46.6)
Amounts reclassified from accumulated other comprehensive income	0.0	0.0
Net current period other comprehensive income (loss)	(181.4)	(46.6)
Ending Balance	(490.0)	(248.8)
Derivative contracts
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(3.3)	(0.1)
Other comprehensive income (loss) before reclassifications	6.1	(3.1)
Amounts reclassified from accumulated other comprehensive income	0.0	0.0
Net current period other comprehensive income (loss)	6.1	(3.1)
Ending Balance	2.8	(3.2)
Pension and post retirement benefit plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(70.7)	(54.3)
Other comprehensive income (loss) before reclassifications	(3.4)	(3.3)
Amounts reclassified from accumulated other comprehensive income	0.7	0.6
Net current period other comprehensive income (loss)	(2.7)	(2.7)
Ending Balance	(73.4)	(57.0)
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(382.6)	(256.6)
Net current period other comprehensive income (loss)	(178.0)	(52.4)
Ending Balance	$ (560.6)	$ (309.0)

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

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