Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Taxes [Line Items]
Tax Cuts and jobs act, income tax expense (benefit)			$ 139.2
Tax Cuts and jobs act, incomplete accounting, transition tax for accumulated foreign earnings, provisional income tax expense	$ (0.6)	$ 0.6
Spanish tax settlement
Income Taxes [Line Items]
Effective tax rate	18.70%			22.70%	18.60%	19.60%
Foreign Tax Authority
Income Taxes [Line Items]
Provision for uncertain tax positions	$ 34.4				$ 34.4
2007-2012 | Minimum
Income Taxes [Line Items]
Income tax examination, years under examination					2008
2007-2012 | Maximum
Income Taxes [Line Items]
Income tax examination, years under examination					2017
Other Liabilities
Income Taxes [Line Items]
Unrecognized tax benefits that would impact effective tax rate	30.6				$ 30.6
Accrued interest and penalties	2.5				2.5
Other Current Liabilities
Income Taxes [Line Items]
Unrecognized tax benefits that would impact effective tax rate	1.0				1.0
Accrued interest and penalties	$ 0.1				$ 0.1