Accumulated Other Comprehensive Income - Changes in Components of Other Comprehensive Income, Net of Tax (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($)
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	$ (329.0)
Accumulated Other Comprehensive Income, Ending Balance	(242.9)
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	(193.4)
OCI before reclassifications	134.2
Accumulated Other Comprehensive Income, Ending Balance	(59.2)
Unrealized (Losses) Gains on Securities [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	(0.6)
OCI before reclassifications	0.4
Accumulated Other Comprehensive Income, Ending Balance	(0.2)
Defined Benefit Plan Items [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	(164.8)
OCI before reclassifications	18.0
Reclassifications	2.0
Accumulated Other Comprehensive Income, Ending Balance	(144.8)
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	29.8
OCI before reclassifications	(44.1)
Reclassifications	(24.4)
Accumulated Other Comprehensive Income, Ending Balance	$ (38.7)