Derivatives and Hedging - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Derivative [Line Items]
Notional amount of foreign currency exchange contracts	$ 186,097,000		$ 186,097,000		$ 165,533,000
Actual foreign currency transactional gains (losses)	(1,506,000)	2,479,000	(2,692,000)	2,544,000
Contracts used to hedge exposures in operating results
Derivative [Line Items]
Notional amount of foreign currency exchange contracts	85,637,000		85,637,000		131,311,000
Contracts used to hedge balance sheet exposures denominated in foreign currencies
Derivative [Line Items]
Notional amount of foreign currency exchange contracts	$ 100,460,000		$ 100,460,000		$ 34,222,000