Financial Instruments and Hedging Activities (Fair Values of Derivative Instruments Included on Consolidated Balance Sheet) (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	$ 349.7	$ 246.1
Liability Derivatives Fair Value	(59.0)	(50.2)
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	209.3	108.2
Liability Derivatives Fair Value	(40.0)	(42.3)
Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	140.4	137.9
Liability Derivatives Fair Value	$ (19.0)	$ (7.9)