Derivatives and Hedging Activities - Effect of Derivative Instruments on Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	$ (10.3)	$ (52.3)	$ 67.8
Interest expenses	201.8	199.4	211.0
Designated as Hedging Instruments | Interest Rate and Currency Swap
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	1.0	20.8	31.6
Interest expenses	2.5	5.1	5.9
Designated as Hedging Instruments | Cash Flow Hedge
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	(2.4)	(25.2)	35.4
Designated as Hedging Instruments | Cash Flow Hedge | Foreign Currency Forward Contracts
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	0.9	0.6	9.6
Designated as Hedging Instruments | Cash Flow Hedge | Interest Rate and Currency Swap
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	(3.4)	(25.9)	25.7
Designated as Hedging Instruments | Cash Flow Hedge | Treasury Lock
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	0.1	0.1	0.1
Designated as Hedging Instruments | Fair Value Hedges | Interest Rate Swaps
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	0.5	0.5	0.4
Not Designated as Hedging Instruments | Foreign Currency Forward Contracts
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	(8.4)	(27.6)	32.0
Not Designated as Hedging Instruments | Foreign Currency Forward Contracts | Discontinued Operations
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Earnings on Derivatives	$ 0.8	$ (32.2)	$ 22.4