Accounting Policies - Accumulated Other Comprehensive Loss by Component, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 9,835.2	$ 2,874.6	$ 2,869.1	$ 2,828.5
Other comprehensive income (loss) before reclassifications			(213.6)	(166.6)
Amounts reclassified from accumulated other comprehensive income			1.6	5.9
Net current period other comprehensive income (loss)	(179.4)	(49.5)	(212.0)	(160.7)
Ending Balance	9,729.4	2,910.4	9,729.4	2,910.4
Foreign currency translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			(202.2)	5.1
Other comprehensive income (loss) before reclassifications			(208.9)	(159.1)
Amounts reclassified from accumulated other comprehensive income			0.0	0.0
Net current period other comprehensive income (loss)			(208.9)	(159.1)
Ending Balance	(411.1)	(154.0)	(411.1)	(154.0)
Derivative contracts
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			(0.1)	4.0
Other comprehensive income (loss) before reclassifications			(3.0)	(8.5)
Amounts reclassified from accumulated other comprehensive income			0.0	4.3
Net current period other comprehensive income (loss)			(3.0)	(4.2)
Ending Balance	(3.1)	(0.2)	(3.1)	(0.2)
Pension and post retirement benefit plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			(54.3)	(54.1)
Other comprehensive income (loss) before reclassifications			(1.7)	1.0
Amounts reclassified from accumulated other comprehensive income			1.6	1.6
Net current period other comprehensive income (loss)			(0.1)	2.6
Ending Balance	(54.4)	(51.5)	(54.4)	(51.5)
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(289.2)	(156.2)	(256.6)	(45.0)
Net current period other comprehensive income (loss)	(179.4)	(49.5)	(212.0)	(160.7)
Ending Balance	$ (468.6)	$ (205.7)	$ (468.6)	$ (205.7)