Black-Scholes Valuation Assumptions of Warrants Issued (Detail)	12 Months Ended
Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Dividend rate	0.00%
Annualized volatility	39.00%
Expected life of warrants (years)	5 years
Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Risk free interest rate	0.59%
Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Risk free interest rate	1.20%

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

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- Definition

Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

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Risk-free interest rate assumption used in valuing an instrument.

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