Accumulated Other Comprehensive Income - Changes in Components of Accumulated Other Comprehensive Income, Net of Tax (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($)
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	$ (329.0)
Accumulated Other Comprehensive Income, Ending Balance	(303.4)
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	(193.4)
AOCI before reclassifications	113.9
Accumulated Other Comprehensive Income, Ending Balance	(79.5)
Unrealized (Losses) Gains on Securities [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	(0.6)
AOCI 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)
AOCI before reclassifications	16.3
Reclassifications	6.0
Accumulated Other Comprehensive Income, Ending Balance	(142.5)
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	29.8
AOCI before reclassifications	(53.0)
Reclassifications	(58.0)
Accumulated Other Comprehensive Income, Ending Balance	$ (81.2)