Derivative Instruments and Hedging Activities - Derivative Instruments Designated as Fair Value Hedges (Detail) - Interest Rate Swaps [Member] - Interest Expense [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) on Instrument	$ (3.8)	$ 10.8	$ 10.1	$ 10.0
Gain (Loss) on Hedged Item	$ 3.8	$ (10.8)	$ (10.1)	$ (10.0)