Income Tax Provision Benefit Allocated to Components of Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Tax Components Of Other Comprehensive Income Loss [Line Items]
Cumulative translation adjustment			$ (8.7)
Derivative financial instruments	$ (0.5)	$ (6.0)	2.4	$ (2.9)
Accrued benefit cost	(0.6)	(0.7)	(2.1)	(1.5)
Unrealized gain on investment		1.5
Income tax (provision) benefit related to OCI	$ (1.1)	$ (5.2)	$ (8.4)	$ (4.4)