Income Tax Provision Benefit Allocated to Components of Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Tax Components Of Other Comprehensive Income Loss [Line Items]
Cumulative translation adjustment	$ 3.3		$ (8.7)
Derivative financial instruments	3.7	$ 2.3	2.9	$ 3.1
Accrued benefit cost	(0.4)	(0.4)	(1.5)	(0.8)
Unrealized gain on investment		(1.5)		(1.5)
Income tax (provision) benefit related to OCI	$ 6.6	$ 0.4	$ (7.3)	$ 0.8