Income Taxes - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Tax Credit Carryforward [Line Items]
Unrecognized Tax Benefits Impact on Effective Tax Rate	$ 1.6
Additional deferred tax liability	(21.1)
Deferred taxes not provided for excess of financial reporting over tax basis of investments in foreign subsidiaries	508.4
Cash and Cash Equivalents	584.0	507.3	544.5	689.8
Income Tax Holiday, Aggregate Dollar Amount	3.5
Income Tax Holiday, Income Tax Benefits Per Share	$ 0.04
Deferred income tax benefit	71.3	(309.6)	39.6
Net operating loss carryforwards in Luxembourg	182.0
Excess income tax benefit from stock-based compensation	10.4	8.7
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	86.5
Interest (income) expense related to tax matters	0.8	2.0
Unrecognized Tax Benefits, Income Tax Penalties Expense	0.7
Interest accrued from income tax examinations	19.4	17.5
Distribution Of Segment Retained Earnings Tax Filing Adjustment			7.0
Continuing Operations [Member]
Tax Credit Carryforward [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	55.8
Discontinuing Operations [Member]
Tax Credit Carryforward [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	56.0
Foreign net operating losses [Member]
Tax Credit Carryforward [Line Items]
Decrease in valuation allowance	(11.8)
Non US Subsidiaries [Member]
Tax Credit Carryforward [Line Items]
Cash and Cash Equivalents	$ 555.2