Income Tax Provision Benefit Allocated to Components of Other Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Components Of Other Comprehensive Income Loss [Line Items]
Cumulative translation adjustment
Derivative financial instruments	(6.0)	4.2	(2.9)	(1.2)
Accrued benefit cost	(0.7)	(0.7)	(1.5)	(2.1)
Unrealized gain on investment	1.5			(0.1)
Income tax (provision) benefit related to OCI	$ (5.2)	$ 3.5	$ (4.4)	$ (3.4)