Summary of Notional Amounts Fair Values and Classification of Outstanding Derivatives by Risk Category and Instrument Type (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013 Interest Rate Swap Contracts	Mar. 31, 2012 Interest Rate Swap Contracts	Mar. 31, 2013 Foreign Currency Forwards	Mar. 31, 2012 Foreign Currency Forwards	Mar. 31, 2013 Derivatives Designated As Hedging Instruments Other Liabilities Interest Rate Swap Contracts		Dec. 31, 2012 Derivatives Designated As Hedging Instruments Other Liabilities Interest Rate Swap Contracts		Mar. 31, 2013 Derivatives Not Designated As Hedging Instruments Other Current Assets Foreign Currency Forwards		Dec. 31, 2012 Derivatives Not Designated As Hedging Instruments Other Current Assets Foreign Currency Forwards		Mar. 31, 2013 Derivatives Not Designated As Hedging Instruments Accrued Liabilities Foreign Currency Forwards		Dec. 31, 2012 Derivatives Not Designated As Hedging Instruments Accrued Liabilities Foreign Currency Forwards
Derivatives, Fair Value [Line Items]
Notional Amount					$ 175,000	[1]	$ 200,000	[1]	$ 44,948	[1]	$ 49,823	[1]	$ 19,465	[1]	$ 88,000	[1]
Asset Derivatives Fair Value			652	792					652	[1]	792	[1]
Liability Derivatives Fair Value	$ 318	$ 533	$ 987	$ 223	$ 318	[1]	$ 533	[1]	$ 16	[1]	$ 21	[1]	$ 987	[1]	$ 223	[1]

[1] Notional amounts represent the gross contract amounts of the outstanding derivatives excluding the total notional amount of positions that have been effectively closed through offsetting positions. The net gains and net losses associated with positions that have been effectively closed through offsetting positions but not yet settled are included in the asset and liability derivatives fair value columns, respectively.