Derivatives - Schedule of Gains (Losses) for Derivatives Designated as Fair Value Hedges (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative Instruments Gain Loss [Line Items]
Total (gain) loss recognized as ineffectiveness in the Condensed Consolidated Statements of Operations	$ 0.2	$ (0.2)	$ (0.2)	$ (0.8)
Interest Rate Swap | Investment and other expense-net
Derivative Instruments Gain Loss [Line Items]
Total (gain) loss recognized as ineffectiveness in the Condensed Consolidated Statements of Operations	(2.2)	1.3	(3.6)	(0.4)
Hedged Items | Investment and other expense-net
Derivative Instruments Gain Loss [Line Items]
Total (gain) loss recognized as ineffectiveness in the Condensed Consolidated Statements of Operations	$ 2.4	$ (1.5)	$ 3.4	$ (0.4)