Summary of Notional Amounts of Outstanding Foreign Exchange Forward Contracts, Designated as Net Investment Hedges (Detail) - Net Investment Hedging [Member] € in Millions, ¥ in Millions, £ in Millions	Dec. 31, 2015 EUR (€)	Dec. 31, 2015 GBP (£)	Dec. 31, 2015 JPY (¥)	Dec. 31, 2014 EUR (€)	Dec. 31, 2014 JPY (¥)
Long-Term Debt [Member]
Derivative [Line Items]
Derivative Notional Amount	€ 400.0
Contracts to Sell Euros for USD [Member]
Derivative [Line Items]
Derivative Notional Amount				€ 50.0
Contracts to Sell GBP for Euros [Member]
Derivative [Line Items]
Derivative Notional Amount | £		£ 21.2
Contracts to Sell Japanese Yen for USD [Member]
Derivative [Line Items]
Derivative Notional Amount | ¥			¥ 19,400.0		¥ 19,400.0