Cash Flow Hedge Derivative Gains and Losses Recognized in AOCI and the Amounts Reclassified to Earnings (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest Rate Option Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Net Gain/(Loss) Recognized in AOCI		$ 0.7
Net Gain/(Loss) Reclassified from AOCI to Earnings
Net Gain/(Loss) Reclassified from AOCI to Earnings	$ 5.2	1.2
Asset And Liability Management | Foreign Exchange Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Net Gain/(Loss) Recognized in AOCI	(1.2)	(9.4)	$ 2.1
Net Gain/(Loss) Reclassified from AOCI to Earnings
Net Gain/(Loss) Reclassified from AOCI to Earnings	(9.9)	2.8	(4.7)
Net Gain/(Loss) Reclassified from AOCI to Earnings | Interest Rate Option Contracts
Net Gain/(Loss) Reclassified from AOCI to Earnings
Interest Income	5.2	1.2
Net Gain/(Loss) Reclassified from AOCI to Earnings | Asset And Liability Management | Foreign Exchange Contracts
Net Gain/(Loss) Reclassified from AOCI to Earnings
Other Operating Income	(8.0)	3.3	(2.1)
Other Operating Expense	$ (1.9)	$ (0.5)	$ (2.6)