Derivatives - Schedule of Gains (Losses) for Derivatives Designated as Fair Value Hedges (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments Gain Loss [Line Items]
Total gain recognized as ineffectiveness in the Condensed Consolidated Statements of Operations	$ (0.2)	$ (0.7)
Interest Rate Swap | Investment and other expense-net
Derivative Instruments Gain Loss [Line Items]
Total gain recognized as ineffectiveness in the Condensed Consolidated Statements of Operations	(2.3)	(0.1)
Hedged Items | Investment and other expense-net
Derivative Instruments Gain Loss [Line Items]
Total gain recognized as ineffectiveness in the Condensed Consolidated Statements of Operations	$ 2.1	$ (0.6)