Accumulated Other Comprehensive Income - Changes in Components of Accumulated Other Comprehensive Income, Net of Tax (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2016 USD ($)
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	$ (329.0)
Accumulated Other Comprehensive Income, Ending Balance	(339.3)
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	(193.4)
AOCI before reclassifications	55.6
Accumulated Other Comprehensive Income, Ending Balance	(137.8)
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	17.3
Reclassifications	3.8
Accumulated Other Comprehensive Income, Ending Balance	(143.7)
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	29.8
AOCI before reclassifications	(43.3)
Reclassifications	(44.1)
Accumulated Other Comprehensive Income, Ending Balance	$ (57.6)