Derivatives and Hedging Activities - Effect of Derivative Instruments on Condensed Consolidated Statements of Operations (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	$ 2.1	$ (5.7)	$ 7.2
Designated as Hedging Instruments [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	15.5	2.8	1.6
Designated as Hedging Instruments [Member] | Foreign Currency Forward Contracts [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	1.9	2.7	(0.1)
Designated as Hedging Instruments [Member] | Interest Rate And Currency Swaps [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	13.5
Designated as Hedging Instruments [Member] | Treasury Lock
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	0.1	0.1	1.7
Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	1.8		1.0
Not Designated as Hedging Instruments [Member] | Foreign Currency Forward Contracts [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	$ (15.2)	$ (8.5)	$ 4.6