Accumulated Other Comprehensive Income - Changes in Components of Other Comprehensive Income, Net of Tax (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance		$ 85.9
Accumulated Other Comprehensive Income, Ending Balance	(31.5)	85.9
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	159.6
OCI before reclassifications	(152.7)
Accumulated Other Comprehensive Income, Ending Balance	6.9
Unrealized Gains on Securities [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	(0.4)
OCI before reclassifications	0.6
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	(143.4)
Reclassifications	3.9
Accumulated Other Comprehensive Income, Ending Balance	(139.5)
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	70.1
OCI before reclassifications	52.4
Reclassifications	(21.6)
Accumulated Other Comprehensive Income, Ending Balance	$ 100.9