Types of Risk Management Derivative Instruments Not Formally Designated as Hedges and Their Notional Amounts and Fair Values (Detail) (Nondesignated, USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Notional Value	$ 246.3	$ 168.8
Fair Value Asset	0.8	1.0
Fair Value Liability	5.3	1.2
Foreign Exchange Contracts
Derivative [Line Items]
Notional Value	246.3	168.8
Fair Value Asset	0.8	1.0
Fair Value Liability	$ 5.3	$ 1.2