Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Fair Value Measurements [Line Items]
Difference between carrying amount and fair value of long-term debt	$ 8.0		$ 9.0
Foreign Exchange Forward Contracts | Not Designated as Hedging Instrument
Fair Value Measurements [Line Items]
Derivative, term of contracts	3 months
Derivative, notional amount	$ 409.3	$ 421.1
Net fair value of contracts	(0.8)	1.5
Foreign Exchange Forward Contracts | Not Designated as Hedging Instrument | Other Income Expense Net
Fair Value Measurements [Line Items]
Gain on derivative	13.7	15.9
Foreign Exchange Forward Contracts | Not Designated as Hedging Instrument | Prepaid Expenses and Other Current Assets
Fair Value Measurements [Line Items]
Fair value derivative assets	0.6	2.6
Foreign Exchange Forward Contracts | Not Designated as Hedging Instrument | Other Accrued Liabilities
Fair Value Measurements [Line Items]
Fair value derivative liabilities	$ 1.4	$ 1.1