Commitments and Contingencies - Additional Information (Detail) (USD $)	9 Months Ended
Sep. 30, 2013
Commitments And Contingencies Disclosure [Abstract]
Potential loss range minimum	$ 0
Potential loss range maximum	27,700,000
Total awarded value for damages to plaintiffs	$ 27,700,000

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Amount of damages awarded to the plaintiff in the legal matter.

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-Name Accounting Standards Codification

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-SubTopic 20

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The estimated maximum amount of possible loss from the contingency.

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

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-Name Accounting Standards Codification

-Topic 450

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-Subparagraph (b)

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The estimated minimum amount of possible loss from the contingency.

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