Financial Instruments and Concentration of Credit Risk - Additional Information (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Outstanding forward foreign currency contracts	$ 0	$ 0

The amount of foreign currency that the entity has contractually agreed, or for which it has the option, to buy or sell with respect to the contract being described.

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