Accumulated Other Comprehensive (Loss) Income - Changes in Components of Other Comprehensive Income, Net of Tax (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)
Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income, Beginning Balance	$ (329.0)
Other Comprehensive Income, Ending Balance	(434.0)
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income, Beginning Balance	(193.4)
OCI before reclassifications	(130.0)
Other Comprehensive Income, Ending Balance	(323.4)
Unrealized Gains (Losses) on Securities [Member]
Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income, Beginning Balance	(0.6)
OCI before reclassifications	0.5
Other Comprehensive Income, Ending Balance	(0.1)
Defined Benefit Plan Items [Member]
Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income, Beginning Balance	(164.8)
OCI before reclassifications	12.1
Reclassifications	9.9
Other Comprehensive Income, Ending Balance	(142.8)
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income, Beginning Balance	29.8
OCI before reclassifications	28.3
Reclassifications	(25.8)
Other Comprehensive Income, Ending Balance	$ 32.3