Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued [Abstract]
Balance at beginning of period	$ 271.9	$ 246.7	$ 226.9
Increases as a result of tax positions taken during a prior year	65.9	6.3	65.0
Decreases as a result of tax positions taken during a prior year	(10.8)	(8.1)	(47.5)
Settlements with taxing authorities	(6.5)	(0.8)	(4.6)
Lapse of statutes of limitation	(1.7)	(3.3)	(11.8)
Increases as a result of tax positions taken during the current year	16.6	31.1	18.7
Balance at end of period	335.4	271.9	$ 246.7
Income Tax Contingency [Line Items]
Unrecognized tax benefits that would impact effective tax rate	313.5
Income tax penalties and interest accrued	42.4	27.9
Income tax penalties and interest expense	14.5	$ 7.0
Minimum [Member]
Income Tax Contingency [Line Items]
Anticipated decrease in unrecognized tax benefits	15.0
Maximum [Member]
Income Tax Contingency [Line Items]
Anticipated decrease in unrecognized tax benefits	$ 25.0
Foreign Tax Authority | Minimum [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Date	Jan. 01, 2019
Foreign Tax Authority | Maximum [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Date	Jan. 01, 2038