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
	Mar. 31, 2016	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) on Instrument	$ 10.8	$ 7.2
Gain (Loss) on Hedged Item	$ (10.8)	$ (7.2)