Accumulated Other Comprehensive (Loss) Income, Net of Related Tax (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]
Currency translation adjustment	$ 365.8	$ 274.5
Net unrealized losses on derivative contracts	(23.0)	(22.0)
Net unrealized gain on investments	6.9	6.6
Employee benefit plans	(473.6)	(478.1)
Total accumulated other comprehensive loss	$ (123.9)	$ (219.0)	[1]

[1] The December 31, 2011 consolidated balance sheet has been derived from audited financial statements.