Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Tax Note Textuals [Line Items]
Deferred Tax Asset Valuation Allowance, Change in Assessment	$ (22.9)	$ 0.0	$ (0.3)
Aggregate Net Tax Expense from US Tax Reform	(2.6)	129.2
Net operating loss carryforwards in Luxembourg	265.9
Excess Tax benefit from stock activity	$ 2.2	2.7
Excess tax benefit from equity compensation activity			3.2
The tax benefits recognized in the Consolidated Financial Statements from such positions are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement	The tax benefits recognized in the Consolidated Financial Statements from such positions are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement.
Estimated change in unrecognized tax benefits	$ 9.0
Interest (income) expense related to tax matters	(0.9)	(2.4)	(2.9)
Interest accrued from income tax examinations	3.2	4.1	6.8
Tax Matters Agreement, Collection			14.8
Tax Matters Agreement, Additional Collection		1.5
Tax Matters Agreement Receivable, Total	2.1
Continuing Operations [Member]
Tax Note Textuals [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	19.9
Discontinued Operations [Member]
Tax Note Textuals [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 1.9
Impacts from U.S. Tax Act of 2017 [Member]
Tax Note Textuals [Line Items]
2018 U.S. Federal Statutory Tax Rate	21.00%
2017 U.S. Federal Statutory Tax Rate	35.00%
One Time Provisional US Tax Expense on Post 1986 Foreign Earnings	$ 4.0	57.9
Tax Expense on Undistributed Foreign Earnings		14.7
Remeasurement of US Net Deferred Taxes	1.4	86.0
Deferred taxes not provided for excess of financial reporting over tax basis of investments in foreign subsidiaries	59.1
Existing Post 1986 Foreign Earnings Subject to One Time US Tax	1,042.7
Foreign Tax Authority [Member]
Tax Note Textuals [Line Items]
Deferred Tax Asset Valuation Allowance, Change in Assessment	$ (22.9)	$ 0.0	$ (0.3)