Summary of Notional Amounts of Outstanding Foreign Exchange Forwards, Cash Flow Hedging (Detail) € in Millions, $ in Millions	Sep. 30, 2016 EUR (€)	Sep. 30, 2016 USD ($)	Dec. 31, 2015 EUR (€)	Dec. 31, 2015 USD ($)
Contracts to Purchase USD with Euros [Member]
Derivative [Line Items]
Derivative Notional Amount | $		$ 263.1
Contracts to Sell USD for Euros [Member]
Derivative [Line Items]
Derivative Notional Amount | $		$ 298.6		$ 70.1
Contracts to Purchase Euros with Other Foreign Currencies [Member]
Derivative [Line Items]
Derivative Notional Amount	€ 36.3		€ 35.5
Contracts to Sell Euros for Other Foreign Currencies [Member]
Derivative [Line Items]
Derivative Notional Amount			1.4
Contracts to Sell Euros for GBP [Member]
Derivative [Line Items]
Derivative Notional Amount	€ 22.7		€ 23.1