Fair Value Measurements - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Fair Value, Measurement Inputs, Disclosure [Line Items]
Maturity period limit of foreign currency exchange instruments (in months)	1 month
Net fair value gain (loss) on foreign exchange forward contracts	$ 0.6	$ 0.7
Difference between carrying amount and fair value of long-term debt	13		15
Other Income Expense Net
Fair Value, Measurement Inputs, Disclosure [Line Items]
Gain (loss) on foreign exchange forward contracts	(6.9)	2.3
Prepaid Expenses and Other Current Assets
Fair Value, Measurement Inputs, Disclosure [Line Items]
Net fair value gain (loss) on foreign exchange forward contracts	1.8	0.9
Other Accrued Liabilities
Fair Value, Measurement Inputs, Disclosure [Line Items]
Net fair value gain (loss) on foreign exchange forward contracts	1.2	0.2
Foreign Exchange Contract
Fair Value, Measurement Inputs, Disclosure [Line Items]
Notional amount of foreign exchange forward contracts not designated as hedging instruments	$ 472.3	$ 409.0