Derivative Instruments Notional Amount Outstanding (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Forward currency contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative instruments outstanding	$ 145,373	$ 147,078
Interest rate swap [Member]
Derivatives, Fair Value [Line Items]
Derivative instruments outstanding	$ 100,000	$ 100,000

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant