Derivative Financial Instruments - Summary of Outstanding Foreign Exchange Derivatives Designated as Net Investment Hedges of Foreign Currency Risk (Detail) - Sell [Member] - Designated as Hedging Instrument [Member] - Foreign Currency Forward Contract [Member] - Cash Flow Hedges [Member] € in Thousands, £ in Thousands, CAD in Thousands	Sep. 30, 2015 GBP (£) DerivativeInstrument	Sep. 30, 2015 CAD DerivativeInstrument	Sep. 30, 2015 EUR (€) DerivativeInstrument	Dec. 31, 2014 CAD DerivativeInstrument
CAD [Member]
Derivative [Line Items]
Number of Instruments	1	1	1	1
Notional Amount | CAD		CAD 162,000		CAD 42,525
GBP [Member]
Derivative [Line Items]
Number of Instruments	1	1	1
Notional Amount | £	£ 96,900
EUR [Member]
Derivative [Line Items]
Number of Instruments	1	1	1
Notional Amount | €			€ 50,000