Accumulated Other Comprehensive Income - Changes in Components of Other Comprehensive Income, Net of Tax (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance		$ 367.1
Accumulated Other Comprehensive Income, Ending Balance	85.9	367.1
Foreign Currency Translation [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	401.1
OCI before reclassifications	(241.5)
Accumulated Other Comprehensive Income, Ending Balance	159.6
Unrealized Gains on Securities [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	0.5
OCI before reclassifications	(0.5)
Reclassifications	(0.4)
Accumulated Other Comprehensive Income, Ending Balance	(0.4)
Defined Benefit Plan Items [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	(67.6)
OCI before reclassifications	(80.0)
Reclassifications	4.2
Accumulated Other Comprehensive Income, Ending Balance	(143.4)
Cash Flow Hedges [Member]
Other Comprehensive Income Loss [Line Items]
Accumulated Other Comprehensive Income, Beginning Balance	33.1
OCI before reclassifications	55.9
Reclassifications	(18.9)
Accumulated Other Comprehensive Income, Ending Balance	$ 70.1