Summary Information about Forward Contracts to Sell US Dollars and Buy Indian Rupees (Detail)		6 Months Ended
Jun. 30, 2013 USD ($)	Jun. 30, 2013 Designated as Hedging Instrument INR	Jun. 30, 2013 Designated as Hedging Instrument USD ($)
Derivatives designated as net investment hedges:
Notional amounts	$ 238,000,000		$ 75,150,000
Weighted exchange rate		59.4
Weighted average maturity		4 months
Other assets			0
Other liabilities			$ (3,214,000)

Average period remaining before foreign currency exchange rate derivatives mature or expire, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_AverageRemainingMaturityOfForeignCurrencyDerivatives1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration