Derivatives - Schedule of Gains (Losses) for Derivatives Designated as Fair Value Hedges (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments Gain Loss [Line Items]
Total (gain) loss recognized as ineffectiveness in the Consolidated Statements of Operations	$ (0.4)	$ (0.4)	$ (0.8)
Interest Rate Swap | Investment and other expense-net
Derivative Instruments Gain Loss [Line Items]
Total (gain) loss recognized as ineffectiveness in the Consolidated Statements of Operations	0.4	(1.7)	(2.1)
Hedged Items | Investment and other expense-net
Derivative Instruments Gain Loss [Line Items]
Total (gain) loss recognized as ineffectiveness in the Consolidated Statements of Operations	$ (0.8)	$ 1.3	$ 1.3