Income Taxes - Narrative (Details) - USD ($) $ in Millions			12 Months Ended
		Aug. 15, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating Loss Carryforwards [Line Items]
Undistributed earnings of foreign subsidiaries reinvested indefinitely for which no provision have been provided			$ 6,300.0
Unrecognized tax benefits liability, interest and penalties accrued			82.0	$ 63.5	$ 52.1
Unrecognized tax benefits, including income tax penalties and interest accrued			501.7	398.0	340.3
Unrecognized tax benefits that would impact effective tax rate			204.0	248.7	198.5
Penalties and interest expense		$ 163.6				$ 24.7	$ 40.2	$ 61.5	$ 37.2
Tax cuts and jobs act of 2017, change in tax rate, income tax expense (benefit)			(2.4)
Tax cuts and jobs act, transition tax for accumulated foreign earnings			17.5
Tax cuts and jobs act 2017, undistributed accumulated earnings of foreign subsidiary			1,200.0
Non-US Taxing Authority | Expires tax Year 2019
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards			1.8
Non-US Taxing Authority | Expires tax year 2022
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards			20.3
Non-US Taxing Authority | Expires tax Year 2024
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards			0.9
Non-US Taxing Authority | Expires tax year 2025
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards			0.1
Belgium Taxing Authority
Operating Loss Carryforwards [Line Items]
Income tax expense as a result of Belgium Tax Act			24.1
Income tax benefit as a result of Belgium Tax Act			33.2
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Valuation allowance increase (decrease), amount			(10.3)
Tax credit carryforwards	[1]		82.6
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Valuation allowance increase (decrease), amount			42.4
Foreign Tax Authority | United States | Expires tax year 2022
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards			28.2
Foreign Tax Authority | United States | Expires tax year 2025
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards			37.2
Foreign Tax Authority | United States | Expires tax year 2027
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards			167.8
Minimum
Operating Loss Carryforwards [Line Items]
Decrease in unrecognized tax benefits is reasonably possible			1.0
Maximum
Operating Loss Carryforwards [Line Items]
Decrease in unrecognized tax benefits is reasonably possible			17.9
Omega
Operating Loss Carryforwards [Line Items]
Valuation allowance increase (decrease), amount			$ (55.8)
Europe
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit), adjustment of DTA and DTL				$ (4.0)	$ (27.9)

[1] Utilization of such carryforwards within the applicable statutory periods is uncertain.