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Derivative Financial Instruments - Notional Amount and Fair Value of Foreign Currency Forward Contract (Detail) In Thousands, unless otherwise specified	Jun. 30, 2013 Financial Institution Counterparties [Member] CAD	Jun. 30, 2013 Financial Institution Counterparties [Member] EUR (€)	Dec. 31, 2012 Financial Institution Counterparties [Member] EUR (€)	Jun. 30, 2013 Financial Institution Counterparties [Member] Other Assets [Member] Non Designated as Hedging Instrument [Member] CAD	Jun. 30, 2013 Financial Institution Counterparties [Member] Other Assets [Member] Non Designated as Hedging Instrument [Member] EUR (€)	Dec. 31, 2012 Financial Institution Counterparties [Member] Other Assets [Member] Non Designated as Hedging Instrument [Member] EUR (€)	Jun. 30, 2013 Customer Counterparties [Member] CAD	Jun. 30, 2013 Customer Counterparties [Member] Other Liabilities [Member] Non Designated as Hedging Instrument [Member] CAD
Derivative Counter Party [Line Items]
Forward contracts - assets				19,573	€ 1,077	€ 1,093
Forward contracts - liabilities								19,552
Forward contracts - assets	588	2	3
Forward contracts - liabilities							(567)