Types of Risk Management Derivative Instruments Not Formally Designated as Hedges and Their Notional Amounts and Fair Values (Detail) - Nondesignated - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Notional Value	$ 397.4	$ 246.3
Fair Value Asset	0.2	0.8
Fair Value Liability	14.6	5.3
Foreign Exchange Contracts
Derivative [Line Items]
Notional Value	244.6	246.3
Fair Value Asset	0.2	0.8
Fair Value Liability	3.7	5.3
Other Financial Derivatives
Derivative [Line Items]
Notional Value	152.8	0.0
Fair Value Asset	0.0	0.0
Fair Value Liability	$ 10.9	$ 0.0